I will own to bias here, as I am no lover of partial desaturation. I find the choice of blue as the only colour to remain makes the photo look very cold. I would suspect that you are trying to draw attention to the contrast between the historic dress and the intrusion of 21st century paraphenalia, but I feel it would have been better left.
let your photograph do the talking. it doesn't need the the obvious "hey i desatted it because I need you to see my point". I don't dislike desat, just saying...