Metalic fabric dress -- disclaimer I don't know much about dresses, the wife bought this a while ago but ended up not wearing it and figured she'd resell it. Tag says it's a medium. I was able to hunt this dress down online (included in the link below). Screenshotted the website's model shoot of this dress, the model is wearing a size S (4 US) and the model is 5'9. 

https://poshmark.com/listing/NWT-SHOWPO-MOXIE-COWL-GLOMESH-DRESSBLACK-6449475fb635f813fb02a7f8