This is not a definite thing, it all depends on what your userpic ends up like. You allow us to list you in our User List - this is purely for research purposes, to show how many people we've worked for. This will be a link to your LiveJournal profile using your LiveJournal username - no emails or anything like that. Of a decent size. Same reason as above.
Small images lose clarity and quality when enlarged.
However huge images are not always better. Please try and cap your image size at 640 x 480. This isn't necessary, but preferred. Images that are too large will be resized and cropped at our discretion to get you what you want. We will not work with illegal, offensive or otherwise obscene images.