Sumuhurtham:In the hindu marriages at the sumuhurtam, precise auspicious moment, with the cloth veil still upheld, the bride and the groom place and hold a paste made of cumin seeds and Jaggery, over each other's heads (on the crown of the head where the opening of Sushumna nadi through which Kundalini enters) The cloth veil is then removed, unveiling the "new' life in holy matrimony. This is the first time the bride and groom look at each other.
Why the cumin seeds and jaggery paste :Positive Electric charge emanates when cumin seeds and jaggery are combined and a paste made of it, as is happened when the glass rod rubbed with silk cloth (In the case of glass rod, electrons are loosely bounded compared to silk cloth and hence it loses electrons &get positive charge and it gets the ability to attract the nearby particles). In the crown of the head, a subtle or esoteric aperture will be there. When this paste is placed on the top of this esoteric aperture which remains closed, gets opened and the positive energy enters through this hole, it travels through Sahasrara Chakra reaches the Ajna Chakra and energizes it(centre of spiritual energy- placed between the two eyebrows otherwise called Bhrumadhya or Bhrukuti).
The bride and groom when looks at each others Bhrukuti (when the veil removed/put down,) their brain wave lengths meet. When the wave lengths of two persons coincide, they think alike and there is no chance of contradictions. This gives them the pleasurable married life.