You can add a Profile photo to your NetGalley reader profile by logging into your account and clicking on the arrow next to the silhouette icon at the top of the page. Choose "Profile" from that drop-down menu.
Click "Change Photo" under the profile photo and browse your computer to add a photo.
Please note: The file size limit for your photo is 500KB, and cannot exceed 254 x 254 pixels. The image will be cropped to a square.