I got what you meant, it works for me on Jeroba. Tapping on the image, in comments, brings up the image viewer and you can zoom in/out.

Mine does, just tap on the image to bring it up by itself and zoom to your heart's content.

What is the web comic this comes from? I tried zooming in on the text at the bottom but it artifacted too much to read.

The problem with these types of redundancy schemes is that it simply takes a Internet backbone hiccough (or AWS fuck up) to cause there to be multiple primaries (i.e. lemmy.world is online still, but some portion of the internet can't see it, so a replica promotes itself to primary, people use both, how do you reconcile it).

This is not even beginning to talk about the nightmare scenarios possible if someone hacks a replica.

Edit: Still, this is a good thought and similar to how some actual software packages do things.