Polka dot shirt/dress

I purchased this as a dress from a vintage shop. There is no tag, I would say it would definitely fit up to a 16. There is a tiny hole in the back by the collar and a small discoloration spot. There are also two small slits on either side that appear to be the way it was made, but I’m not quite sure why. The dress is about 35 “ long., pit to pit is about 25”, the width of the bottom is about 42” laying flat. The last 3 pictures show the spot, the tiny hole and the slit.