First off, this is mainly vBulletin's code and it's not exactly PHP. Just so you know in the future.

In a postbit you have to use the $post variable. Here's the code you would want to try:
<if condition="$post['profilepic']">
<img src="images/hasprofile.gif" alt="Has a profile pic" />
</if>

That should work inside the template to complete what you're after.