When having a png, pdf, jpeg, gif etc. open, it Firefox would usually show a little icon for it on the tab bar, showing you what image is opened on it without having to be on the tab (this only worked when the image wasn't too big or the there weren't too many tabs open at once). However, these icons don't show up anymore at all since the last update. I tried refreshing the tabs several times, even closing them and opening them again, yet to no avail. This makes it difficult to know which one of the images you have opened is the one you need, as all tabs only show the title of the image, not what image is on it. I'd just like to know if this is a bug, if that feature was simply removed, or if there's some setting that I can enable to make them show up again.

Thanks in advance! :D