Profile image caching on remote servers

!Hubzilla Support Forum
When I first installed hubzilla on, I uploaded a personal profile logo (g2).  A couple of days later, replaced it with a better site logo (afterpod).

I still see the g2 logo appearing on Mastodon as well as sometimes on Hubzilla servers (if I click over to read a message).  I assume it is cached but wonder what the mechanics of that are.

If you're connected with somebody on a site, profile photo updates take a day or two. If you aren't connected with somebody on the site it's a bit less predictable. I don't know what Mastodon does. I'm currently providing an updated timestamp on the photo object in Osada, but not from hubzilla. I don't know of anybody else who reads and processes these updated timestamps but I think it's the most sensible approach. I think most other projects just provide a cache timer on the entire profile and refresh it at some point whether anything changed or not. The cache duration is anybody's guess. But just like Hubzilla, if they aren't getting any regular communications from you by virtue of being connected with somebody on the site, they need some kind of communication from you to kick off the refresh.
I see.  Have asked a Q at a Mastodon site... will try to learn what it does.

Here is an example w/Hubzilla on both sides. If connected, system updates changes to the profile image.  If NOT connected, old/original icon remains even after many visits, etc.

I found this MASTODON function for admins but it appears to be global maintenance rather than a cache update routine.  This part of the issue is definitely on their side.