You can find out more in the sidebar of the instance
Edit: On the web you see it on the right side when you are in the main page. On Jerboa click the 3 dots on top right and then site info. On thunder I can't find it and I don't have liftoff installed to check.
Doesn't mean anything to me. For example, my Mastodon instance admin is someone with a name and picture. This is completely fine since, as he states, we're trusting him with our data, so it's only fair the users know who he is.