First off, a general comment about Shiori - I find it very strange that she isn't wearing glasses. Usually, bookworm type girls are wearing glasses, just take Yuki from Haruhi as the most noteable example.
Something I didn't like about this episode was that Keima was once again purposefully trying to make the girl mad
Then I saw the girl in the galge Keima was playing on his PC-FX Portable:
Now it became clear to me: Shiori can't stand up to cute Vermouth-chan and her twintails. Keima was angry because Shiori wasn't wearing twintails, and thus didn't treat her that nicely. Yes, that must be it!
Keima's reaction towards Elsie was quite arrogant:
One should think he would be more appreciative of her by now, but he's got still the same cold attitude
Shiori flying through the library as a little fairy was nicely done:
We also got some infos about Shiori in that scar-y side story, which gave us the most freaky Keima saying so far. Reading her inner monologue through her liver!?
Finally, another nice game screen at the end. Anyone got it without that text window?
All in all a nice episode, but -1 for Keima being an ass and -1 for Shiori not wearing twintails like Vermouth-chan, so 8/10