If doing this often I’d copy the page we are about to go to, and make my own component. This is perfectly good for “one time” however.

PeopleTools > Portal > Portal Utilities > Navigation Collections

Add a new Navigation Collection (we won’t save it). Once you enter a Name and move to anothe field the ‘Override Default Options’ group box displays.

Click ‘Add folder’

Click the search button on ‘Override Image’ and you are presented with a well handy little page to view images.

example