As far as the girls and their pimps are concerned, punting is a mugs game and we're simply there to get milked of cash. When a Romanian girl sees us, all they see is a £100 note glued to the forehead.
Many of the girls are pimped or trafficked. Others who aren't trafficked may have sound reasons for the families not to know they are whoring (I've known girls at risk of physical violence if the family found out). The pimps are acting illegally - often they are the front men for criminal gangs. So it stands to reason they're going to try to obfuscate the girls identity by using fake profiles/photos.
They don't want the girls identities to be traceable by the police. By changing the profile photos (and sometimes names) it becomes harder for the police to match girls in the brothels to the adverts, so when the police followup on AW or VS profiles by visiting the house they can't prove linkage.
And of course some girls get multiple profiles using different pictures just to attract a wider clientele: at present there's a barebacker in Preston using six profiles. If some punters walk, well she doesn't care: she's double booking in the assumption some WILL walk when they meet her.
But back to the main point: the girls and pimps are acting illegally, or on the edge of legality and they don't want to be caught. Hence the fakes.
And just to make things clear: this isn't an attempt at justification, just explanation