Even our teacher respect me to a certain degree.
Chinese idiom "敬...三分" (lit. Respect someone to a 30% degree) expresses an idea of showing a certain degree of respect out of one's own consideration. For example, one would do this to random senior stranger since he is old, or one would do this to a junior governor because he holds power. The respect showing one here is actually in a stronger position, and bothers little, if any, by the negative impact from not showing respect.
Here in the emouticon's case, a pun is used. Individually, "三分" literally means "3 points", which is exactly what Mokou got from her Math test.