What does 1曲リピートボタン 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 1曲リピートボタン?

HTC first drew 1曲リピートボタン in Sense 7, released 2015年3月30日.

HTC Corporation has shipped 2 versions of 1曲リピートボタン. Each is dated, so you can see when the design changed.

HTC

HTC Corporation has drawn 1曲リピートボタン 2 times. Every revision HTC has shipped is below, newest first.

What does 1曲リピートボタン 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 1曲リピートボタン?: HTC first drew 1曲リピートボタン in Sense 7, released 2015年3月30日.
How many times has HTC redrawn 1曲リピートボタン?: HTC Corporation has shipped 2 versions of 1曲リピートボタン. Each is dated, so you can see when the design changed.

HTC artwork for this emoji spans 2015 to 2016.