The default member profile image is a generic male figure as seen below.
Don't worry ladies, you don't have to use that image. :) To use a Bookhuddle-provided female image, simply click on the "My Account" link on the top right corner of any page and update the "Gender" field to be "female". This will change your profile image to the female default image below.
You can always upload your own image via the "My Account" -> "Picture" tab.