The point the teacher was trying to say is that emotions the painting conveys matter more in painting and art than the picture itself.
It's not even that realistic, if noble society was like this in the past revolts would have happened yearly, most societies with nobility required the nobles to act more like a guide to the commoners, not like they were another species entirely, , the disdain you see for "noveau riche" characters in alot of stories is actually more realistic to this, hence why the merchant class had certain restrictions placed on them in most feudalistic systems, to prevent stuff like this.