Google image search or Tineye are your friend.
But even without that here is a good rule to follow:
If the lady in the picture looks TGTBT and the add says "outcall only" (or in other words, I will show up at your home, hotel or office, not being even close to what the pictures depicted but because you will be afraid of the scene I will make when you turn me away, you will end up either taking a crappy session and getting ripped off or paying me to go away) then it likely is a scam/B & S.
Cheers
J