If I understand correctly there is no way to restrict the post categories in pages using one of the blog templates (Blog Image Medium, Blog Image Large etc.). I guess a work around would be to create menu item to one of the categories, which would display posts only belonging to that category. My question is what template does it use, the page that comes up when you make a link to a category? I would very like it to be Blog Image Medium, but I don’t which one it is using.