First of all, I think students are generally simple-minded and don't think a lot of twists and turns. The question says that teachers care about students and often chat with them. It can be seen that teachers have strong personality charm, are relatively approachable and kind-hearted, so I think students should like teachers better.
Secondly, the problem is that the teacher is old, ugly and fat, but I think as a teacher, appearance is secondary. Teachers care about students and often chat with them, which shows that her personality charm is still great, so students like to look directly at teachers because they like to be close to them.
Finally, always staring at the teacher makes it easy to learn and regress. Good luck!