If, like myself, you like taking screenshots of GDQ but don't want to play it in an external app to support the stream: I wrote a quick userscript that adds a screenshot button
https://gist.github.com/eramdam/377b5be7de525fe8cfd23484e1696978
(yes this is the Instagram icon, i couldn't find a "photo" icon in Twitch's UI so this will have to do)
@Eramdam haha, nice
@noiob modern problems, modern solutions, etc etc :P
@Eramdam it's a shame that Firefox's "save snapshot" feature doesn't work because they block the <video> context menu
@noiob yeah, im sure you could put an extension together to add a context menu entry but even then a lot of players with custom UIs block the first right click.
Maybe I should make a "add screenshot button" extension for a bunch of video-playing websites 
@Eramdam no, I mean, the Firefox context menu has a "Save snapshot as…" entry usually, I use it all the time on Youtube
@Eramdam do it on an exposed video (right-clicking twice on Youtube works), it'll show a bunch of video-related entries
@Eramdam it's nice because it just saves the current video frame, so it's not affected by screen resolution
@noiob still wish it didnt prompt the "save as" dialog :P
@Eramdam https://bugzilla.mozilla.org/ :P
but yeah, idk, it's obviously not a focus
@noiob i just noticed my userscript already respects the video's dimensions 😎
Oh also you can press F9 and it does the screenshot automatically as well. It might blank out the video for some reason if you do it too many times in a short time, don't know why 🤷