i really am new to this been poking around for a while couldnt really call myself a PUA still, but have had quite a few vids and pics off girls in my time i tell ya ha, iv always got em thru texting or BBM, but yeh realistically for a girl to send you a naughty pic or video you would have to have already built enough rapport with her for her to feel comfortable enough to 'want' to send it anyway, if that makes sense.. so it shouldn't be that hard really, it just depends on how adventurous the girl is herself.
id say your best bet would be to wait until night time because you can be talking about blah blah woteva then say your going to go to bed, eventually she will go to bed as well or may already be in bed woteva, so now your both in your bedrooms in your beds alone... hmmm... make sure to mention how cold your bed is an how it would be warmer with her in it blah blah then jus tell her you would love a pic to go sleep with, she might try and send you a silly picture, and as its not upto standard id say something like ''noooo i meant a naughty one i wanna see your gorgeous ****

she may say ''my gorgeous what?'' id just say ''bum ha'' or ''suprise me :p''
as for in the day time we'd already be chatting (over BBM) then after talking about a completely different subject id say ''unoo.... '' *to build suspense* '' i wanna naughty pic of uuu lata

she'd probably laugh it off but i tell her im serious and its her fault if anything for being too pretty and making you excitede while walking down the street or think naughty thoughts then repeat something similar to the above process lata that day
its just me chatting rubbish and thinking off top off head really, i talk to girls even just for jokes not always with the intention of meeting and fucking them, you can learn a lot from keeping girls as friends, god knos, but maybe you can take something from this, just test different methods out on all you #closes practice makes perfect and im sure you'll be cool