What does Bright Button look like on Facebook?

On Facebook it is the design shipped in 16.0, shown above at full size. Older revisions are listed beneath it.

When did Facebook add Bright Button?

Facebook first drew Bright Button in 2.0, released February 20, 2017.

Meta Platforms, Inc. has shipped 12 versions of Bright Button. Each is dated, so you can see when the design changed.

Facebook 4.0

Facebook shipped a new design for Bright Button in 4.0, released April 1, 2019. The previous design is shown beside it.

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

What does Bright Button look like on Facebook?: On Facebook it is the design shipped in 16.0, shown above at full size. Older revisions are listed beneath it.
When did Facebook add Bright Button?: Facebook first drew Bright Button in 2.0, released February 20, 2017.
How many times has Facebook redrawn Bright Button?: Meta Platforms, Inc. has shipped 12 versions of Bright Button. Each is dated, so you can see when the design changed.