The system offers two ways to create pages:
as panel pages, where you create, style, and fill boxes;
and as layout pages, where you enter html for the body of your page and
css to style it.
Any page can be included in any other, so you can create header panels and
include them in your own handcoded layouts.
You can also upload media files, and crop and adjust uploaded images.
You can try the functionality here (though you will not
be able to build or do anything that saves the page):