This is just the typical fediverse proposed logo but edited to make it more accurate to how instances actually defederate from other instances.
Found it in an old thread about different proposals for the logo https://socialhub.activitypub.rocks/t/fediverse-logo-or-icon-proposal/1057/9

the image from this comment in specific https://socialhub.activitypub.rocks/t/fediverse-logo-or-icon-proposal/1057/14

see also https://stefanbohacek.com/blog/the-history-of-the-fediverse-logo/

i just think it’s neat