That is actually a serious question, and it has nothing to do with the personal bias or motivations of the author.
I was once shown an algorithm for removing red-eye from photos, and noticed that every example they showed, was of drunk white Irish people (usually with light eyes). Turned, out, the library didn't do so well, for other skin tones.
[EDITED TO ADD] I actually enjoyed the heck out of it. Many of the comments, below, explain why it seems that way. Also, it may just be "the luck of the draw." I suspect that most images are from a common demographic, because that was who the photographers that supplied the images, came from. The tech, itself, seems to be quite basic, and is a fun idea.