The "Sign Up" feature of the Meetings section of the environment provides a tabular view of upcoming meetings. The "Date" column can be sorted and provides an image next to the text "Date" that indicates whether the list is currently sorted by ascending or descending values. However, this image is not provided an <alt> attribute and therefore screen reader users will be unable to discern the purpose of the image.
Developers must ensure that all images in the environment are provided a valid <alt> value. As this image represents whether the list is currently sorted in ascending or descending values, the alt attribute must provide this information as well.