RidemCowboy
You'll need to go into your User CP & then click on
"Edit Avatar" But, you know your original pic might be somewhat too wide since it's really quite horizontal.
I tried to go into my photostudio & make your avatar less wide. I managed to eliminate some of the width by moving the horses closer & cropping out that horse behind you. Bumper might still need to resize it for you or allow it. I don't know but, I tried. Here it is.
Here is your original photo. I can't compact it any more without losing your subject unless you just want a silhouette of yourself on horseback.