It was hanging on the mannequin windows. It was too cute and sparkly to be real. But it was too small. After the ''recognition round'' around the store, trying some things, and taking this black and comfy pumps, I decided to go to the kids section, just being curious about. And as you can see, I found it! It's the biggest size from kids, and fits pretty well because I'm not very tall hahaha. I think it's a little bit childlike and may remind a princess costume, but I thought it was a nice idea for a party, and I really liked its white/cream color and shape, which is also very comfy (you know: not too short, not too long).

I also bought another similar dress from this section in blue with sequins (this one is a sort of mermaid/princess costume). Wore it the last night with the classmates before holidays for a party, and they just loved it! Conclusions about of all this: 

I was wearing:

H&M kids princess dress

H&M black pumps

Backstage cuff

Karen Millen sparkly bag