I might have created too high expectations and Mr. Brickmuppet is not entirely impressed. Although I seem to recall he used to same reaction for Midori no Hibi too, which went down as a rousing success later.

Meanwhile, Sage attracted my attention to the original source manga, available at SenManga. Here's a spoiler:

The page corresponds to a skit in 02, where Otako digs her own grave. She starts another conversation about toilets and segues to male and female anatomy. I strongly suspect she only does it in order to enjoy Galko's embarrassed reactions. But as she is forced to explain, she gets embarrassed herself in a karmic retribution. Just as she finds a way to escape, Ojou crushes her with "あー、子宮かぁ". I have to say, hear Minami Takahashi say that really enrichens the experience, but manga got it perfectly. Look how Ojou is outside the picture because Otako habitually forgot about her, and only appears in the last frame to stab her.

As you can see, anime script follows manga quite literally, but its designs are different in parts. Someone sure didn't want to animate every strand of Galko's hair. By the way, I do not see a manga styled in "color pencil" often.