I think he might have asked whether the person was asking for permission or whether it was about making a request.
Is that asking for permission to take a photo, or asking someone to take a photo for them?!?
I think when morau comes after a -te verb, then it becomes a request. So basically, "Can you take a photo for me?"
totteageru -- Can you let me take a photo for you/someone else
tottekureru -- Can you take a photo for me? And then give to me
tottemoraemasenka -- Could you let me take a photo? Simply giving the person permission to take a photo. Who will get the photo afterwards is irrelevant.
not entirely true. http://jisho.org/search/moraeru. If this is to be believed, it could also mean something like. 俺に写真を取ってもらえませんか. if the おれに is specified, then it could mean "Could you take a photo ( and give it to me) please? However, morau for example doesn't necessarily explain whether you are letting someone do something or forcing someone to do something. It simply says that you (by whatever mean) HAVE someone do something. So then it would be like "Could I have you take a photo? The person with the camera who asks the permission wants the photograph, but is not asking for permission, simply the favor of taking the photo, and if oreni is declare, then it means to ask the favor of taking the photo, then giving it to me. So morau has more to do with favors, not permission. Give me a biscuit, a favor, not a question of permission. You are already seated so you are entitled to the cookies.
So morau is more the favor of giving to me. Ageru is permission to do something for someone, and kureru is permission to do something.
君が俺に写真を取ってもらえませんか Could you take a photo (for me)
俺が写真を取ってあげますか Am I allowed to take a photo (for you)
君が俺に写真を取らせてくれませんか Would you allow me to take a photo (for me/or someone else)
There you got it.