Quoting Peter
I could also make it so the link on the stream page changes to "Back to <username>'s Profile" instead of "Back to Gallery" in the situation where they came from a profile. Might be the clearest option for people.
Yes, I think that's the sort of amendment I had in mind. In my head (and I suspect other people's?) if I go 'back' I expect to go back to where I came from, not somewhere else entirely!