Noticed this while I was following Threads users via micro.blog (who have turned on Fediverse syndication).
No profile avatars for Zuck and Adam. Probably same with other Threaders as well. Not sure if this is a known glitch? Mastodon users who I follow seem to have their avatar in place as usual 
It’s a known issue and I’m working on. Longer answer: Mastodon makes a copy of profile images, but Micro.blog just tries to cache them temporarily. The problem is Threads is very picky about letting people request the profile image URL after a certain period of time. So depending on when it’s cached, Micro.blog will get an error from Threads, leading to the blank images.
