What does 重复按钮 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 重复按钮?

Facebook first drew 重复按钮 in 2.0, released 2017年2月20日.

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

Facebook 13.0

This is the design Facebook introduced in 4.0, shipped again unchanged. It was not redrawn for this release.

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

What does 重复按钮 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 重复按钮?: Facebook first drew 重复按钮 in 2.0, released 2017年2月20日.
How many times has Facebook redrawn 重复按钮?: Meta Platforms, Inc. has shipped 12 versions of 重复按钮. Each is dated, so you can see when the design changed.