You have shared a screen shot of your entire desktop. The fact we cannot read text in it without zooming into the image is not really the fault of the forum sortware. The forum displays the image the author has shared. It is up to the author to think about what they are sharing and their audience as to whether the image is helpful or not
On mobile I can at least pinch/zoom to get a better look.
What do you mean by full size? For me (after clicking the image) it shows at the maximum size it can in the browser window without losing stuff at the edges or changing the aspec ratio, does that not happen for you?
Do you mean that when you click on it, it initially shows smaller than it was before you clicked it? If so then that is a browser issue. For me it does not open a new window, it just expands it to fill the current window, both in Waterfox and Chrome. That may well be a browser setting somewhere, or perhaps you are using IE.
No. In the thread it is "scaled" to be smaller and fit in the window/thread.
I get that.
When I click on it, it does become bigger - and I maybe picked a bad example - but it isn't optimised to be as close to its original size as it could be.
I am saying that and could be wrong. This is why I am wanting to ask/discuss it.
This is a fairly pointless thread. We have no control over how the forum displays images. If you have feedback, take it up with https://discourse.org
As I said before - whoever is posting an image needs to consider what they want to show. If they want to show a message in the debug sidebar, then sharing a full resolution screenshot of the entire desktop is not that helpful.
It can't make it much taller because it needs room for the the x at the top, don't know why you are seeing a small gap at the bottom, I don't see that. It can't make it any wider without messing up the aspect ratio. As I suggested I think it is your browser wasting that little bit on the bottom rather than the forum.
On m 27" monitor when I click on it to zoom it, I can read that text quite easily.