What is the term for the condescending usage of "we" that essentially means "you"? For example, when talking to a child, you might say "we need to be on our best behavior." A slight variant could be the instructive tone commonly found in mathematical proofs, e.g. "we see from (xxx) that (yyy), which tells us that (zzz)..."
I thought for quite some time that this was the meaning of "the royal we", but it turns out that is a different thing. What is the condescending usage actually called?