If anything it seems to make it look more blurry, at least the original version has defined edges

Pretty sure you’re right there, Imgur galleries used to contain ads when viewed in Sync

It’s strange, both on Sync for Reddit and Sync for Lemmy I’ve always seen the space for ads, but never an actual ad showing in that space. So I just get random black spaces between posts

Sync now supports “blocking” communities, which tells Lemmy that you don’t want to see that content. Much more effective than filtering because it also transfers to the site, so desktop will reflect the blocks.

I believe you’re correct, all 5 pixels of that tp seem to be visible