In my POV, I think it's the opinion. Maybe......?
It's going to be setting. Although it was using past pretenses like "was" it isn't a backstory, it wasn't describing the characters or any event. It was only describing the room, the setting. Hope this helps :).
<em>They provide us with both a snapshot and a background to the social and political histories of the analytical method, colouring and outlining it with reality. While this is of some academic interest, biography also creates a far more engaging and lively platform for historical interest.</em>
The sentence which is an effective example of I-language:
"I don't like having to remind you about your chores."