It's like one of those spot the difference games, but finally the picture of Kelly on the right was deemed to have large enough buns to keep TfL happy.
The play's producer, David Pugh, said "Someone is sitting in a dark room somewhere peering at any sort of nudity. The whole truth of the story that I'm doing is about this group of ordinary women who did something extraordinary. I'm replicating what they did. They said we were trying to titillate Tube travellers, I thought it was a joke."
With a quote more suitable to a Carry On film than an transport statement, Metro said a spokesman from TFL said they asked for "a few tweaks" to make sure the advert complied with their policy.
This isn't the first time PhotoShop has been used to make an advert comply with London Underground's policy on decency.