Areas of the plant that get more sunlight grow faster and usually have larger colas. Its why some people in flowering defoliate the bottom most branches that are not getting any light whatsoever, its just a waste of energy and usually yield small little popcorn buds when that energy could be directed towards the areas that are flourishing. Im not sure about veg but I think the same thing applies. I lollipop so I cut away all the small little new growth at the bottom a week or two before flowering