Image Width on Pages with Comic Easel

I want to post images on a page at 900px wide. But they seem to be restricted to a certain width, even though “disable sidebars” has been selected.

Text will stretch across the whole width of the page, as will grids and tables of other images, but a single image will not go wider than 500 or 600px even when put into a table.

You can see the page I’m having trouble with here: website

The source images for all of these images are 900px (the header is 1200px) so it’s not an issue of re uploading bigger images.

Thanks!