User blog comment:DiegoAnime3000/RWBY's characters new models!/@comment-4010415-20140214080510/@comment-24053809-20140214081956

As Monty stated in a behind the scenes feature on the dvd, he wants the characters to grow up as the years pass by. Unlike traditional anime it seem like no matter how long the shows been on air for, the characters never seen to age.

And remember that RWBY is a fairly new show and that the technology that the guys are using behind it (Poser Pro) is still new to them. Monty will be upgrading the characters rigs every so often so that they will apear to age as the show continues throughout the years and these cards might also be examples of the work that their doing to improve RWBY.