My first instinct is a skeuomorphic representation, make a big grid of "windows" that load some colors or hashed content from each profile of an instance and display that. But I think something more vauge would wind up working better.
RE: https://stefanbohacek.online/@stefan/115877439199157641
Randomly came across a boost of 
@stefanStefan Bohacek's server connection virtualization just now and reminds me how much these types of things actually help us humans "feel" this thing we exist in. In the ongoing protocol wars we need to lean in to what makes this place unique. We have to show the diversity within the feDIVERSE in as many ways as possible. If all the front pages of instances are a list of trending posts or an about page with some boring text that doesn't show off this diversity of humans!
If you have a fediverse account, you can quote this note from your own instance. Search https://social.wake.st/users/liaizon/statuses/116216812685067416 on your instance and quote it. (Note that quoting is not supported in Mastodon.)