Accessing pic.php with argument s=1 or greater gives much better picture resolution than the original. Is that intentional? The amount of interaction available

Accessing pic.php with argument s=1 or greater gives much better picture resolution than the original. Is that intentional? The amount of interaction available without registration is sadly very small, not compelling to me. Before I invest time in registering, I'd like to evaluate the site much more. At least some sample profiles... Use of OpenID could also streamline the registration or do away with it altogether.