There are many different ways to use the web besides a mouse and a pair of eyes. Users navigate for example with a keyboard only or with their voice.
All the functionality, including menus, links and forms should work using a keyboard only. This is essential for all assistive technology to work properly. The only way to test this, at the moment, is manually. The best time to test this is during development.
Tab through your pages, links and forms to do the following tests:
This post should display a featured image, if the theme supports it.
Non-square images can provide some unique styling issues.
This post tests a vertical featured image.
This post should display a featured image, if the theme supports it.
Non-square images can provide some unique styling issues.
This post tests a horizontal featured image.