Use a tool within the website to provide a crop of your staff image. This crop makes sure the image loads well across the site.
Crop the image
When you first upload the image, click the button that says "crop image", and then provide a crop via moving the square overlay over the image – it's set to only allow a square-size.
The button itself:

When the crop screen opens, you can drag the square box on the right side to show what part of the image you'd like to appear in the crop. There is no wrong way here, (although i assume you'd want to make sure your full face appears). You can leave the original square boundary/crop if that looks good to you.

Editing and cropping the image later
To provide a crop (or new crop) after the image has already been saved, edit the staff profile and scroll to the thumbnail of the already saved image. You should see a pencil icon. When you click on that, you will see a page that looks similar to the fields and of when you upload an image for the first time. Scroll down, and you will see the "crop image" button.

