The fact that you get to look at the order of your prizes even if you aren't playing Ultra Beasts at all is kind of neat.
Seems like you only shuffle them if you choose to pull out an Ultra Beast?
Look at your face-down Prize cards. You may choose 1 Ultra Beast you find there, reveal it, and put it into your hand. If you do, shuffle this Beast Ball into your remaining Prize cards and put them back face down.
It could just simply imply that if you don't have an Ultra Beast in there, you just shuffle the prizes without putting the beast ball in.
I think it's cool that we're getting more cards that interact with prizes in general.
You would have to be running more than 3 or 4 Ultra Beasts in your deck if you wanted to actually utilize the search effect though.