The idea is that all animations are in the center. Heres an example:

This is my base sprite. He's smaller than yours, but he still shows that the canvas he residesin is much larger than he is. This is so the attack animations have room to animate. Here's my attack animation:

the attack animation takes up significantly more space than the base sprite, so the canvas is sized to make up for that fact. So for your sprite, you'd make the canvas large enough so he can still attack while being in the center of the frame