If lag compensation is set to predictive, force attacking with no targets around shows the animation for the attacker, but not for others.
If it is set to none, the attacking player does a step forward with no attack animation.
I remember it not being the case some time ago, and it was a great way to communicate without chat, but now others simply don't see the anination.
Try to attack with no valid targets around and lag compensation on.
You will see the animation, but other players won't.
Do the same but with lag compensation set to none.
Your character will do a weird step forward with no attack animation.