Sewing a Balloon Dress

Dear users, dear authors,
I’ve been wondering for quite a while what these dresses are called that are fairly wide at the bottom and look very comfortable.
I think they’re balloon dresses. Do you know another name for them? Since when have they actually been in style? We don’t have too many of them in the shop yet. As far as I can tell, it’s not the same as a twirly dress, because that one doesn’t have the rounded shape at the bottom?

Here’s an example of a balloon dress from the kids’ section: 
With leggings / tights underneath, it’s sure to be totally cute.

Favorite Balloon Dress/Children’s Dress - sewing pattern & sewing instructions

Twirl dresses have a circle skirt—that is, a skirt that looks like a round plate when you twirl. The sewing pattern for such a skirt is a circle or a three-quarter circle.
A balloon skirt, on the other hand, flares out toward the bottom but is gathered again at the hem, so it takes the shape of a balloon.

I bought a blouse like that a few years ago. It also got wider and wider from the top, and at the bottom band it was gathered with elastic. It immediately reminded me of a balloon dress, since it was also relatively long and I then pushed it up with the elastic. 

I also remember that my daughter used to wear one. I think it keeps coming back into fashion. 

Little girls like a twirly skirt because it flares out so nicely when you spin around. Maybe it’s too much fabric around the legs for some people, but I think they’re quite pretty.