Revealing mistake: When one of Rita's monsters tears a building apart, the buildings are completely hollow, and nothing more than 6 pieces of Styrofoam stuck together to look like a building.
Revealing mistake: When we see the Dragonzord, Tommy is sometimes standing on top of it. However, it is obvious that "Tommy" is nothing more than a small plastic figure.
Answer: Probably to save on costs of filming the same scene. In the reused shots they have always morphed so you can't see the actors. They just have to pay them to do voice-overs rather than the entire scene.
Ssiscool ★