It’s a complete wrap dress and it is long enough that it stays put. It’s silk so it is more pricey for H&M (over $100.) But I think it’s worth the price, the fit is good, the material is thick and structured. The only thing is the sleeves are more of a rounded look so I rolled and scrunched for a more flattering / casual look.
I am in the medium and it runs TTS, maybe even generous. Medium = 8/10.