like most Halachos that are trampled on, it usually means that it is a particularly important Halachah, and the Yetzer Horah spends extra koach to make sure it is light in the eyes of the klal.
i would guess that this is a particularly important inyun because it is disrespectful both to your chaver and to the Shchinah.
lashon horah was once such an inyon, before the Chofetz Chaim began his war on the Yetzer.
SJ this applies if there is not a Mechitzah (such as a support post, a bimah, certain shtenders. a chair and typical table dont qualify.