If it appears in the next episode preview, which it does, I'm betting there's some trick there, especially since that shot is right after the one where she's tied up.
Unless the people who made the episode preview are effing retarded (still a distinct possibility), I'm betting that there's some kind of twist.
When the show itself seems to want you to know, I don't really see too much harm in saying it.
Now, if you're one of those people who can't even watch next episode previews, I guess I can understand.
But we're getting away from the point here.
The point is that Ai-chan tied up in a chair in her suit and glasses is HAWT.