Bhagavad Gita, Chapter 3, Verse 6

He who, restraining the organs of action, sits dwelling in the mind on thoughts of the objects of sense, he, of deluded understanding, is called a hypocrite.

Looking disciplined on the outside means nothing if the mind never actually left.

Sitting still while the mind keeps chasing what it wants isn't restraint, it's a performance of restraint. Real change happens on the inside first, or the outside version is just for show.