What does Keycap: # 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 Keycap: #?

HTC first drew Keycap: # in Sense 7, released March 30, 2015.

HTC Corporation has shipped 2 versions of Keycap: #. Each is dated, so you can see when the design changed.

HTC

HTC Corporation has drawn Keycap: # 2 times. Every revision HTC has shipped is below, newest first.

What does Keycap: # 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 Keycap: #?: HTC first drew Keycap: # in Sense 7, released March 30, 2015.
How many times has HTC redrawn Keycap: #?: HTC Corporation has shipped 2 versions of Keycap: #. Each is dated, so you can see when the design changed.

HTC artwork for this emoji spans 2015 to 2016.