How does the photographer use the technique of filling the frame in this photograph?

Filling The Frame simply means to fill your photograph with more of the subject. So instead of having negative space, or worrying about composition, you're going to get closer {that's where your feet come in, WALK, move closer} and snap it a little closer up. This means that you're removing any distractions.

the answer is   as follows

d

c

b

a

d