Sportmax Code Ruffle Plaid Top Blouse Shirt Size 8 Sleeveless

I honestly don't know how this top works. There is some kind of elastic inside the shirt, which definitely has a purpose. I show a photo of it. I therefor photographed it to the best of my ability. It is a fabric that is a little wrinkly by nature. I tried to steam it for a while but this was the most it went. From a smoke and pet free home Chest: 16.5" Length: 23" No stains, holes, rips, odors