Fragments must be expressive, unmistakable. The emotion has to be conveyed very clearly.

Good Example👇👇👇

Emoji: 😢

Expressive, clearly conveys great sadness without needing actual falling tears.

Bad Examples 👇👇👇

Emoji: 😡

Inexpressive, resting neutral expression.

Emoji: 😱

Unclear, is he trying to sit down?

Fragments must express a single emotion, not a more complex action or state of mind that possibly includes the chosen emoji.

Good Example 👇👇👇

Emoji: 😯

The emotion evolves in two stages, but it's the same underlying feeling.

Bad Examples👇👇👇

Emoji: 😘

A kiss, but not quite a kiss. The emotion behind the fragment is a lot more complex and can’t be reduced to 😘.

Emoji: 😞

Not mere sadness. “Resignation in the face of unfavorable odds”? “Alright, whatever”? The emotion behind the fragment is a lot more complex and can’t be reduced to 😞.

Fragments must actually show the correct emotion.

Good Examples 👇👇👇

Emoji: 😡

Clearly angry, unmistakable.

Emoji: 😨

Clearly afraid, unmistakable.

Bad Examples 👇👇👇

Emoji: 😨

Looks like indifference, not fear.

Emoji: 😱

Expresses anger, not shock or surprise.

Fragments should be an example of a great suggestion you'd get when typing the given emoji as input — showing the same literal action isn't enough.

Good Example 👇👇👇

Emoji: 🤦

This reaction is relevant, it's a response to someone being naïve or unreasonable.

Bad Examples 👇👇👇

Emoji: 😎

There are sunglasses in this scene, but it's not a good suggestion for the emoji, it depicts puzzlement, not "being cool".

Emoji: 🤌

The emoji could superficially describe this fragment, but the emotional content doesn’t match.