What may seemed to look like an ordinary price tag in the front (first picture), turns out to be an RFID tag on its back (second picture).
The RFID tag is put outside the plastic cover of the product, since if it is put beneath it, the seal would have to be broken alltogether. So if you are a cleptomaniac (I am sure you are not!) and you forgot to remove the plastic, the alarm would beep. What if you are accidentally caught without the alarm beeping? Well, they can match the barcode of the product you are holding, with that on their inventory. If it is a match, then you are stealing from them.
That being said, don't steal.
Sent from my BlackBerry® smartphone