What does 重复按钮 look like on HTC?

On HTC it is the design shipped in Sense 8, shown above at full size. Older revisions are listed beneath it.

When did HTC add 重复按钮?

HTC first drew 重复按钮 in Sense 7, released 2015年3月30日.

HTC Corporation has shipped 2 versions of 重复按钮. Each is dated, so you can see when the design changed.

HTC

HTC Corporation has drawn 重复按钮 2 times. Every revision HTC has shipped is below, newest first.

What does 重复按钮 look like on HTC?: On HTC it is the design shipped in Sense 8, shown above at full size. Older revisions are listed beneath it.
When did HTC add 重复按钮?: HTC first drew 重复按钮 in Sense 7, released 2015年3月30日.
How many times has HTC redrawn 重复按钮?: HTC Corporation has shipped 2 versions of 重复按钮. Each is dated, so you can see when the design changed.

HTC artwork for this emoji spans 2015 to 2016.