The window showcase will take a few hours to update. If you don't have any images in your window after about 12 hours, file a support request and they'll fix you up.
When you block a person, they can no longer invite you to a private message or post to your profile wall. Replies and comments they make will be collapsed/hidden by default. Finally, you'll never receive email notifications about content they create or likes they designate for your content.
Note: if you proceed, you will no longer be following .