The rule determines if an alternative description for the image (
alt attribute) contains a filename. Basically, it searches for the filename with following extensions:
Quite often the image contains an alternative description using only a filename. This doesn’t help to understand the image context for screen reader users as well as for search engines. Therefore we recommend to provide a meaningful description of what the image is about.
How to fix it
alt attribute with a filename for the image and instead provide a meaningful description of what the image is about.