In the loading area for the Maelstrom attraction, the Viking sitting in the boat beneath the middle red stripe of the sail is wearing Mickey ears instead of horns.
Journey Into Imagination
In the bathtub scene on the Figment ride, there are 3 bubbles on the side of the tub that form a classic HM.
After the ride, before you get to the gift shop and the exit, there is a room with interactive games... this Mickey is on one of the game's consoles.
When the golf ball heads directly toward you, watch the ball's rotation to see the dark classic Mickey on the surface of the ball.
The Seas with Nemo & Friends
The garbage cans at the Seas Pavilion have HM's in the bubbles.
Living with the Land
It is in the mural to the left of the boats as you are loading.
On the driver's side backseat window of the car outside the "Steve Jobs" scene on Spaceship Earth is a Mickey Mouse sticker.
The cables on the ground near the car formed a classic HM. Tough to see during the ride, but it's very clear on the photo .