I had thought that the way Sync currently behaves was the normal behavior, but after using the pwa (instead of Sync) I can see that it behaves differently between the two.

The pwa keeps the thumbnail blurred until you click on it - even when you go into the post to read whatever. It makes your request make a lot more sense when you see how the website behaves.

You guys probably know that I like my screenshots, so here's my pwa views before clicking the thumbnail and after. (Did you make that feature request?)