Looks like Stelfreeze's take on the original Land haircut from the earliest Dixon days.
Interesting trivia: If you read Birds from the beginning, you can actually basically watch Barbara's hair grow out, from the just-under-the-ears cut she had when she first recruited Dinah to the just-past-shoulder-length when Benes took on art duties. There's some variation, of course, but it's way more consistent than, say, her chair has been post-Dixon.