Guest: Not only that. Why are the heads shaved?
Prabhupāda: That is another variety. So you want variety-less. Is it not?
Guest: No. I am asking why these are necessary. Why are they necessary?
Prabhupāda: They are not necessary for a person who is advanced. But in the preliminary stage we have such necessities. This creates atmosphere, but at the same time, these varieties are not, I mean to say, material varieties. They are spiritual varieties. The place where we are trying to approach, Vaikuṇṭha, there the inhabitants are like this. They have got this tilaka, they have got... Of course, we haven't got four hands, but they have got four hands. There are two hands also. And they are dressed like this. So these things are not material varieties as much as chanting is not material vibration.
Besides that, any path you follow, you have to follow the regulative principles as they are enacted by authorities. So in our disciplic succession, previous ācāryas, they have advised that you should have your dress like this, you should have your head like this, you... So we have to follow that. Mahājano yena gataḥ sa panthāḥ (CC Madhya 17.186). Our principle is to follow the footprints of authorities. So these things are not unauthorized. These are being followed from time immemorial. This dress, this tilaka, this chanting. Everything. Just like you see the picture of Lord Caitanya, we are following the same principles. This was being enacted five hundred years ago. The same principle we are following. We are not introducing anything new. We are simply following the footprints of our predecessors. That's all.