What does Up-Down Arrow look like on DoCoMo?

On DoCoMo it is the design shipped in 2013, shown above at full size. Older revisions are listed beneath it.

When did DoCoMo add Up-Down Arrow?

DoCoMo first drew Up-Down Arrow in 2001, released January 1, 2001.

NTT DoCoMo has shipped 4 versions of Up-Down Arrow. Each is dated, so you can see when the design changed.

DoCoMo

NTT DoCoMo has drawn Up-Down Arrow 4 times. Every revision DoCoMo has shipped is below, newest first.

What does Up-Down Arrow look like on DoCoMo?: On DoCoMo it is the design shipped in 2013, shown above at full size. Older revisions are listed beneath it.
When did DoCoMo add Up-Down Arrow?: DoCoMo first drew Up-Down Arrow in 2001, released January 1, 2001.
How many times has DoCoMo redrawn Up-Down Arrow?: NTT DoCoMo has shipped 4 versions of Up-Down Arrow. Each is dated, so you can see when the design changed.

DoCoMo artwork for this emoji spans 2001 to 2013.