If I could make one suggession, it would be to reduce the indent between comments (they get shifted to the right too far).
Especially now that the colors help to discern them, it's not necessary to shift them that much.
I love how the images get expanded when pushing on the thumbnail (I use compact view), however, I find it annoying to have to push on the thumbnail again to close them, (most of the time i have to scroll back up to reach the thumbnail). I'd rather be able to swipe them right to close them, or something easy (tapping on them?).
Great work on the app, it's really smooth to use, thanks a lot!