The new Mobile HTML editor allows you much greater control over the version of your site that is served to mobile phones. Here is what you can do with it:
Set the colour scheme for your site
You can use the colour pickers on the left-hand menu to customise the visual style of your mobile site. Changes are previewed immediately, and take effect as soon as you click Apply. The back arrow allows you to set all colours back to the site defaults.
Choose how page content is displayed
By clicking on Arrange Content, you can use the grab handles on the right-hand menu to change the order of the elements shown on your mobile site. For certain elements, you can click on the eye icon to toggle their visibility. Click Save to apply any changes that you make here.
The preview window is a fully-functioning replica of your mobile site, so you can use the Menu button to browse to different pages. Colours are applied site-wide, but you can change the order of individual pages this way.