A licensed Yoda puppet was altered to move and was puppeteered by the actress playing Princess Leia.
The holo-projected effect was achieved in the same manner that the original Star Wars: Episode IV - A New Hope (1977) film did the holo-projected Princess Leia. Shooting Yoda against a blue screen with 24fps camera, then while playing the footage on video at (30fps) a camera (24fps) filmed the TV screen. The difference in frame speed created the flicking effect.