If the photos of Perumal and Thayar are separate, must the Thayar photo be placed to the left or right side of Perumal photo? Is there a mandatory requirement as to where Thayar photo should be placed?

Lakshmidevi photo can be placed to the right of Perumal photo and Bhumadevi photo can be placed to the left of Perumal photo. There are no regulations on this. It is a matter of one’s devotional experience.