When I need to copy the link of the thumbnail, I would right click to tab the page of the browser in order to access the address bar.

How were you doing before? Did you do a simply click and after copy the address go back to the page?
Otherwise you can still right click on the thumbnail and chose "copy link" (or "copy target" or something like that, depending on the browsers), as before. Even with the added javascript popup the link at HTML level as not changed.
Or just right click on the enlarged image displayed in the popup and chose "copy image link".
I could easily add a "copy link" button in the popup, if it is handy.

By the way, earlier today I fixed a small bug: the edited comments were always included in the "Last edit: ..." mention the username, but the username is supposed to appear there only when edited by someone else (an admin).

Right, I didn't think about the 'copy image link' when clicking on the image, I just used to copy the link at the top of the page.
Solved

I've noticed a strange bug on mobile. For some reason, i can no longer click on anything on the right half of the page unless i flip my phone sideways. This only happens on this website specifically.

Do you mean that it happens when you are in vertical mode or in horizontal mode?
Which web browser do you use?

It happens with both but it's far more noticeable in vertical mode.

I use Firefox.

I test mostly with Firefox and I didn't had that problem. Maybe it is due to some ads? You could try blocking them just to check if it is caused by that (as they depend on the country, maybe you get some that cause issues)

Small update for the popup of comment images: if a timetag can be guessed from the picture name, it is displayed. There may be cases where it is wrong in some cases, or not detected where it should, I can try to tweak the code if needed.

You can check in the thumbnails I post, e.g. in https://www.imcdb.org/yourcomments.php?formovie=33550045

Just wanted to chime in and say that the mobile site is very unoptimized on Safari on iOS. Sometimes I can't click on links or even the text box if I need to edit a comment.

I suspect issues with some ads (I really should change the ad company), even if not optimized on mobile it should work fine, as it is rather basic pages.
This site is a relic from the 2000-2010s internet It was a little tweaked to make it more usable on mobile, but it is not a mobile-first site like most of the sites nowadays.

Minor update, following a request received, now in the page that appears when one uploads a picture for comments you can simply press the Enter key to copy that URL to clipboard (in addition to Ctrl+C or the "Copy" button at is side).

Discussion about images submission split to a new thread: https://imcdb.opencommunity.be/forum_topic-9967-93534-Submitting_images.html#p93534

Discussion about forum issues was split to a new thread:
https://imcdb.opencommunity.be/forum_topic-9976-93856.html#p93856
This one is about the site itself, for changes made to it.

Maintenance scheduled later today or tomorrow (depending on when I have time), the site will be locked for changes for one or two hours, to apply the changes that were under test in the last week.
The main change is a better handling of the makes, with a predefined list of makes and specific info for each make. This will also allow additional make-related features in the future.

Starting update now.
Some errors may appear while the update is done.

Update done. Please report here any error that you notice.

The changes:

Instead of just having the make name as a text field in the vehicle info, now the makes are stored in a separated table, and each vehicle is linked to a make.
This should improve performance on the long term (as the site is growing), and allows to have some info displayed on the make page.

On the home page https://imcdb.org/ the list of makes is similar as before.
Now for each make there is an option to select if it should appear there or not (before, that list was updated by me once in a while based on the amount of vehicles in it, but some less popular makes on the site may be more worth including there than others. It would still be better to try staying around 250 makes there.
If you check "Triumph" in the list, you'll notice that now the cars and motorcycles are finally split, as they are different companies:
Cars: https://imcdb.org/vehicles_make-Triumph.html
Motorcycles: https://imcdb.org/vehicles_make-Triumph-mc.html
You can see here that each make can include a descriptive text, a link to Wikipedia, and a logo, making the make page a little more cheerful (later I'll maybe add possibility to have a logo gallery, for now one is already nice).
This will have to be done manually for each make, we/I can update them one by one on the main site when we've time.
I also updated the two Sterling pages for the example:
Trucks: https://imcdb.org/vehicles_make-Sterling.html
Cars: https://imcdb.org/vehicles_make-Sterling-Rover.html
I've already downloaded a few logos that I'll set now, I'll continue to do that today and tomorrow to try to put some more logos and info. Currently only one logo can be set per make, I'll see later how I could improve that to have a gallery of old logos.
Please don't include images in the makes info, as the script that cleans unused comment pictures would not detect them there. I'll see for adding that later.

One big interest of having a description on the make page is that we can link between related makes. Here on the Sterling (Rover) page I included a link to the Rover page, and the other way round the link to Sterling on the main Rover page, so visitors know that some of the vehicles are also sold under other names. This can be especially useful for Chinese join-ventures that many makes create.

As you may notice, to differentiate makes sharing a same name, each make has a unique identifier. So a car listed as Sterling 825 like https://imcdb.org/vehicle_901333-Sterling-825-XX.html will have its full name correctly displayed as just Sterling, but the search links include the unique identifier, which I named here "Sterling-Rover": https://imcdb.org/vehicles_make-Sterling-Rover_model-825.html (I still have to fix the title of this page to display the make name instead of its identifier).

The complete make list has also been updated, with a filter for easier search: https://imcdb.org/makes.php

That change means that now when adding/editing a vehicle the make is not stored as text, but just an identifier to the make is kept. For you it does not change much, it should even be easier, as there is an autocomplete text box when you enter the make. You can then pick the appropriate make in the list. If you don't, when saving it will try to find the make that matches the name that you entered, and display an error if no make is found.
For case of new makes, from the home page or from the makes list, there is a link to add a new make. This operation can only be done by admins.
That will avoid having "typo new makes", as we sometimes have.
There are maybe some to clean. I try to check that from time to time but I may miss some.

The code of the search and vehicle list page has been cleaned, as it was an old mess from years ago, but there should not be visible changes. A new option to find the vehicles without model names was added, previously when clicking on the "(none)" link of a make page it was listing all, now there is a possibility to see just these. And there are still links to see all models from the makes page.

Other improvements include how IP ban are handled and options to set header message more easily, but that's a feature just for me

I'll unlock the site for changes, since it seems to work.
Please report here any error / weird behavior that you notice.