Any anime that has a classroom setting probably has this. What is it? You probably wouldn't notice it unless someone brought it up. Let's take a look at some pictures, then find out what they all have in common.
|A Certain Magical Index|
|Kimi ni Todoke|
The significance of this spot? Well in Death Note, Light is able to notice the book outside the window from that position. But other than that, I don't know if there is a specific reason. I think they're there so they can have plot defining monologues, or just to look out the window dreamily while the narrator reiterates said plot. Or maybe it's just so they can eat and sleep unnoticed by the teacher.