My grand daughters are dressed like this for the photo shoots, xmas, mothers day etc. the rest of the time mummy puts them in peppa pig, frozen, princessy type clothes which they love. One day they may blush seeing themselves dressed in the way they like today.
I expect Charlotte is exposed to Disney and enjoys costume type clothes, what I do not expect is her privacy invaded whilst going through this phase.
Just because we have never seen them in their favourite pyjamas does not mean they are not allowed to.