What does Record 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 Record Button?

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

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

Facebook 4.0

Facebook shipped a new design for Record 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 Record 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 Record Button?: Facebook first drew Record Button in 2.0, released February 20, 2017.
How many times has Facebook redrawn Record Button?: Meta Platforms, Inc. has shipped 12 versions of Record Button. Each is dated, so you can see when the design changed.