No idea if this really counts as unexpected, because I don’t know what the expected design is for an RFID shield. I’m going to count it anyway, just because I like the idea.
If you’re staring blankly now and thinking “Hello Kitty what?“, some explanation may help. RFID chips are those little chips that can be read by a reader without having to touch them. Often used for security doors, so you can just wave your pass close to the sensor, and the door unlocks. They’re being used more and more for different types of ID and cards, and a lot of people are a bit paranoid about the fact that they can be read without touching them. Probably not too much of a problem as a quick extra layer of security to stop the public wandering into the back room of a shop or similar, but you might not be so happy about your car keys or credit card being readable by someone standing near you.
These things are just little bags with metal shielding, so an RFID chip inside the bag can’t be read.