What does Digit Four look like on Google?

On Google it is the design shipped in 17.0, shown above at full size. Older revisions are listed beneath it.

When did Google add Digit Four?

Google first drew Digit Four in Android 8.0, released 2017년 8월 21일.

Google LLC has shipped 14 versions of Digit Four. Each is dated, so you can see when the design changed.

Google Android 9.0

Google shipped a new design for Digit Four in Android 9.0, released 2018년 8월 6일. The previous design is shown beside it.

✳ marks a release that redrew this emoji. The rest re-shipped the design unchanged.

What does Digit Four look like on Google?: On Google it is the design shipped in 17.0, shown above at full size. Older revisions are listed beneath it.
When did Google add Digit Four?: Google first drew Digit Four in Android 8.0, released 2017년 8월 21일.
How many times has Google redrawn Digit Four?: Google LLC has shipped 14 versions of Digit Four. Each is dated, so you can see when the design changed.