The images used to visually depict the layout options in the Change Layout interface are missing alternate (ALT) descriptions.
This results in failure of WCAG 1 Level A (baseline) accessibility compliance.
It would be sufficient to copy the current title attribute information for each image into an alt attribute. The radio buttons for selecting layout also need to be wrapped in a fieldset and include a legend.
Reference: http://www.ja-sig.org/wiki/x/ig0
Added alt descriptions. Verified against WCAG 1A and 2L1.
Added labels for inputs and wrapped change layout radio buttons in a fieldset.