DIY T-shirt dress. For the dress on the model, they must have cut the the bottom of the bodice with a slit a few inches long, to tie it and gather it like the top of the skirt. Otherwise, it would just hang from a loose crop top, like in photo #6.
DIY :: Matching Cropped Top and skirt, backless, crop top, matching, prints
▶ DIY Nasty Gal Wrap Crop Top (Sewing) From Tank Top / Body Suit - YouTube