If that too fails, then the browser displays the innermost alternate text.
You need alternate text here to clarify which items are checked or not checked when the images are not visible.
The information, structure, and relationship for elements that can be presented to users through the UI should also be programmatically determined or have alternate text.
There is one difference to note here: because an image button is a click-able form element, you should always provide alternate text for it.
If there is text directly to the right of your image, put a space after the alternate text so that screen readers display and read them as separate phrases.
