To put it all in order, the bee rolls in the pollen at the flower. Combs off the pollen grains with it's back legs, mixes it with nectar that the bee has inoculated with various bacteria (mostly Lactose Bacillus but a few Glucobactors as well) and yeasts and fungi which will ferment it into bee bread and make it digestible. It forms this into a pellet and puts the pellet in it's baskets on it's legs. When arriving at the place to put it, it is popped out of the basket, which a bee can do by herself (unlike propolis which is also carried in the same baskets but require assistance to remove) and after placing it in the pollen cell it is packed by head butting it.