This guideline is targeted at "functional images." Please refer to the image categorization guidance in the Definitions section if you are unsure which category the image you are assessing belongs to.
Test procedure
Confirm the functionality of the image when you interact with it. (Figure out if it is a link or if it is a button that triggers some action.) After doing so, check for the following properties on the functional image.
Every image must have an alt attribute present.
Alternative text for functional images must describe the functionality of the image.
A linked image must have alt text equivalent to the destination. Additional text like "logo of" or "image of" may not be present.
An image that triggers some action needs alt text equivalent to what the label of a normal button that would trigger said action would be.
