Prestiging is used in the Registry. Once you have collected all the foundable stickers on a registry page you are given the option to “prestige” your registry. Prestiging your registry page will remove all the stickers and change the frame. You can then complete the page again to further prestige it.
You can use this as a way of gaining more XP. By resetting the page you have the option to find the foundable again and gain increased XP. Along with bragging rights for higher prestige frames in the registry.
Below is a gallery of the frame currently in the game.