What does 打开的书本 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 打开的书本?

HTC first drew 打开的书本 in Sense 7, released 2015年3月30日.

HTC Corporation has shipped 2 versions of 打开的书本. Each is dated, so you can see when the design changed.

HTC

HTC Corporation has drawn 打开的书本 2 times. Every revision HTC has shipped is below, newest first.

What does 打开的书本 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 打开的书本?: HTC first drew 打开的书本 in Sense 7, released 2015年3月30日.
How many times has HTC redrawn 打开的书本?: HTC Corporation has shipped 2 versions of 打开的书本. Each is dated, so you can see when the design changed.

HTC artwork for this emoji spans 2015 to 2016.