The flag design is beautiful and the black part has good adhesive but the pocket (flag) is already peeling away at the corners.
The part of this this product with the design (the flag in your case) is designed to peel off and be used as a screen cleaner. It should then be able to be stick back on without the need for any kind of adhesive. Sometimes this item can get dirt and dust between the layers and may need to be cleaned a little for it to hold securely.