Okay so it wasn’t actually a very tricky game of spot the difference because Miley Cyrus is 16 and Kim Cattrall is 53, but that’s the whole point of the scene - apparently!
In the movie, Samantha is invited to the premiere of her boyfriend, Smith Jerrod's, new film. In an attempt to look 'hot and young' on the red carpet, she splashes out on a strapless silver dress.
But to her horror, when she arrives at the premiere, she spots Miley Cyrus wearing exactly the same dress.
Anyway, the pair end up posing together on the red carpet, much to Samantha’s discomfort. Same old same old then…