Thunderbird motion is quick, supportive and whimsical.

Quick

Animations should be fast and nimble, never keeping the user waiting longer than is necessary. The aim is to prioritize user-perceived performance over technical benchmarks.

Supportive

Motion should help ease the user through the experience. It should aid the flow of actions, giving clear guidance for user orientation: spatial or temporal.

Whimsical

Animations should have a playful and delightful personality when appropriate.