I have been using the forum on my phone over the weekend while I was away from my computer. I was using Firefox in Android 4.3. I discovered that it's not possible to zoom images uploaded to the forum. They just fill up the width or height of the display, which is way too small if you're trying to view detail in a high-res image (like the full-screen grab in this comment). Even on a larger computer display this would still be an occasional issue, for example to examine detail in a 4k video grab on a lower resolution display. This can be done by downloading the image (e.g. via right click) and viewing it externally or in a new browser window/tab, but it would be nicer to be able to do it within the forum itself. Please add this functionality if possible.