This shot glass has a bit of something extra inside: Freeze Gel!
The glass is double-walled, and trapped within the walls is ice-pack type freezey gel substance (That's probably also blue or clear) You can put the whole tiny glass into the freezer to chill the gel, then it keeps your drink cold while you drink it, without diluting it with ice.
But really...why? The glass is so tiny that there's not that much liquid to keep cool for a long time. Stuff like this gel is usually in thermos, travel cup, or a tumbler type cup to keep drinks quite cold for a while. Still, it's a fun thing to have.
The design is simply forward-facing classic Sonic, without any outlines, on a blue background. No black ink is used, so the eyes/nose are also blue. It's nothing super design wise, but the gimmick is fun. This is a 2017 item at Spencers' Gifts.