Eureka! Why didn’t I see it before? Is this all that’s involved? I wish someone would have shown me this before. Animation seems so easy now…

Actually, this makes me dizzy just watching it…

Jamaal Bradley posted this on Vimeo recently. Milt Kahl did Medusa (and the reflection!), while Ollie Johnston did Penny. My initial reaction (starts at the 0:11 second mark).