Okay, this one is odd in that it's NOT...not one that is.

You're not getting 1 embed. Not even 2 or 3 embeds.

THIS IS SEVEN EMBEDS!

So you're getting 7 embeds for the price of one.

This is a breasts bursting out of a shirt embed. Each embed has the size breast its meant for.

Small, Medium, Large, Huge, Enormous, Gigantic (in that order) as well as User

Timmy: Wait, but Mongoose, what size is User?

Mongoose: That's a good question Timmy, and the answer is...whatever you want it to be...or a mystery if you're lazy. Now get back in your cage and keep cranking out embeds!

So User stands for User Generated. It's meant for 2 different use cases.

Case 1: The Character you're using it for already has a defined breast size that may interfere with one of the other embeds. You might find this with LoRA's, other Embeds, or even model coded characters. Use User in that case if one of the others doesn't work for you.

Case 2: You only want to get one embed and just control what happens in each pic with prompt changes. In your case just put in the User embed and follow it with "<size> breasts". (Some people may have luck with just "<size>" but I don't suggest it because odd things can happen.)

TTFN!