WordPress Plugin Staff List – Circular Images
It’s quite simple to apply the circular effect to your images. If you want to keep things perfectly round, use images with the same width and height. Anything else will still be rounded, but you’ll end up with an elliptic shape which may or may not be desirable.
Image dimensions WxH: 200×200 pixels.
Image dimensions WxH: 200×237 pixels.
Notice that the bottom image is more oval-shaped/oblong than the top one.
How to Set Up a Circular Style.
Staff Template > Template Options > Image > Circular Image