I want the default image to only always show at the top of the posts pages.
So in the header. I already have a plugin/theme that puts the featured image as the header for the page.
Basically we set a 150px x 150px featured image on posts, which then displays in the wiki. However when you view the post you get a distorted mess at the top, we want to keep the current featured image for posts but only display the default image at the top when you view them.