What does Check Mark Button look like on Samsung?

On Samsung it is the design shipped in One UI 8.5, shown above at full size. Older revisions are listed beneath it.

When did Samsung add Check Mark Button?

Samsung first drew Check Mark Button in Touchwiz 2.0, released April 26, 2013.

Samsung Electronics has shipped 26 versions of Check Mark Button. Each is dated, so you can see when the design changed.

Samsung Experience 9.0

Samsung shipped a new design for Check Mark Button in Experience 9.0, released February 11, 2018. The previous design is shown beside it.

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

What does Check Mark Button look like on Samsung?: On Samsung it is the design shipped in One UI 8.5, shown above at full size. Older revisions are listed beneath it.
When did Samsung add Check Mark Button?: Samsung first drew Check Mark Button in Touchwiz 2.0, released April 26, 2013.
How many times has Samsung redrawn Check Mark Button?: Samsung Electronics has shipped 26 versions of Check Mark Button. Each is dated, so you can see when the design changed.