On a wall inside the restaurant, groupings of circles are on a poster entitled "Adventure Thru Inner Space". The circles in the middle right of the poster approximate a classic Mickey.
Circles make a Mickey hat with ears on the upper part of the control panel behind C-3PO’s head, at the lower center of the upper screen.
If you exit through the front of the attraction after riding the submarines, you'll find a classic Mickey on a rock wall near the elevator for the monorail.
The major continent on the planet Ska-densii shown in the queue (and the exit) of the Buzz Lightyear Astro Blasters ride bears a resemblance to a certain rodent...
On the Captain EO ride, take a look at the thrusters on the back of Captain EO's ship. There are four thrusters; two big and two little. The two little thrusters and the bottom big one form a Mickey.