Endermen make stare sound even when provoked by attacking

I had found an enderman and I wanted to attack it WHILE LOOKING AT ITS FEET,it raged at me and that static stare sound played

What I expected to happen was...:
When You hit an enderman,it would simply scream at you and attack you

What actually happened was...:
Whenever I attack the enderman (I am looking to the feet),it makes that long,tragic stare sound plays along with the enderman's screams

Steps to Reproduce:
1. Find an enderman
2. Attack it while looking at its feet
3.it will make that static sound while raging