It is a pochette for iPhone 7 plus or other mobile.
(Please check the size below because it may not fit depending on the case and cover your mobile's wearing.)
Each design on the front and back are different.
It can be the pouch also for cameras, memo pad, pencils, plastic bottle as in 5th picture or even ICOS / iQOS, ICOS Case as well.
It should be very useful if you want to make baggage compact or at the summer festival or at some other location where you need to deposit your main bags at a lobby.
Moreover, since the structure connecting the one of the cords through the hole of the eyelet can adjust the length of the cord, it becomes a convenient sub pocket if you attach it to the handle of the backpack or the handbag (refer to the 4th picture -its not the item itself ,just a sample-)
Size (Unit cm)
Cord Length :120 (If its too long for you, it can be shortened by joining the part passed from the eyelet)
Pink +White Khaki+Gray(code)