Imo I would imagine he's asking if he can have a current photo of you, to confirm you look like your profile pics, as he's asked after asking for a date but he's maybe not being straight enough to tell you outright (maybe as not to sound shallow or then having to cancel a date on the basis you look different to what he thought, which could come across as hurtful).

Someone has asked the same of me before for the same reason as above, which I thought was fine and reasonable, as everyone will undoubtedly put their best photos they've ever taken in the profile and what with that, angles etc they aren't always reflective and can be borderline dishonest in cases.

I have also had it where someone has looked drastically different to their pics in real life which is a waste of everybody's time.