That's clearly the Evil Dora from an alternate time line. In her time line, her love for Marty goes unrequited while Marten and a happy-go-lucky Faye enjoy a healthy relationship. In a fit of jealousy, she steals Raven's time machine (Raven is actually a brilliant physicist, more on this later) to strike at Faye at her weakest point: her father. Using her powers of seduction, she leads him down a path of adultery, drug addiction, and ultimately suicidal despair. The comic you point to is her checking in on herself and Marten at the moment they become involved. She's basically ensuring the success of her plan. Raven tried to go back to stop Dora, but Dora (who we know has some rather strong computer skills) hacked the time machine's central computer before she left, so Raven wasn't able to get back far enough. Unable to to save Faye's father, she settled for the next best thing: she befriended Dora and tried to gently guide her towards good. She knew that having a brilliant scientist play Yoda would just bother Dora, so she adopted the persona of ditsy sidekick, all the while giving Dora things to be happy about, occasionally reminding her to think of puppies, and most of all, conspiring to ensure that she gets the man she wants, because Raven knows too well the consequences if she doesn't.
Either that, or Jeph just likes drawing faces like that.