more and more hairs then the buds will fill out and become more solid...........the hairs will change colour and wither into the bud as it swells.......
what strain do you grow? as weeks go by you will see the hairs start growing some volume... you start seeing clusters of them tucked up on the branch (if you're doing things right), and seed pods (with no seeds in them) will appear at the base of the hairs.
It very amazing to watch. In time the bracts will become more and more and has they do the flower gets bigger and bigger. it really gets fat and huge the last 2 weeks.