I've never liked the "my" prefix for labels because it wasn't immediately obvious whether "my" referred to me, or to the person/company/entity/software which created the thing.
This is particularly annoying when error messages are written from the point of view of an entity or fictitious person, e.g. "Sorry, I wasn't able to..." but things on screen are labeled "My..." Is "me" the user or the software?
Back in the Windows 9x days, Windows didn't refer to itself with first-person pronouns. That was a development that occurred a few years after "My Computer" morphed into "This PC".