Forgive my ignorance, cos I don't FB and I know nothing about studio interiors, but did Phil actually say he was working with Bon Jovi there or is that just an assumption ppl are making? I saw some questions about that in the comments, but no answers.

It makes me wonder if he could have been recording with someone else when that picture was taken, since he's a session musician. I get the impression he works with lots of different artists as well as BJ. Plus, around a month ago, didn't Jon say (again) that the record was finished?

Of course, as you said, it could be a rehearsal situation; not necessarily recording.