Here you have a collection of cartoons I have watched that include some form of Magical Girl transformation. On the left you have transformations that include the heroes having their normal clothes removed, revealing their naked but featureless bodies, before their costumes appear, and usually one piece at a time. And on the right you have the transformations that have the costume immediately replacing the civilian clothes. Notice that the column on the right seems to be lacking (though it could probably have a few more I don’t know about because I haven’t watched those shows).
My point is, when I first saw the Miraculous Ladybug transformation I found it weird that she didn’t have her civilian clothes stripped from her before the costume took their place, which is what I’m used to with other transformation sequences.
I find it weird that they didn’t strip down a young girl (which is what all of these examples are by the way) for her transformation sequence. What does that say about the shows I used to watch?