The picture in a Web publication does not contain alternative text that describes the picture.
Alternative text (also called ALT text) is useful to Web site visitors who have text-only Web browsers or slow connections, who turn their graphics display off, or who use screen-reading software.
To find and select the item, click the error message in the Design Checker task pane, click the arrow, and then click Go to this Item.
Add Alternative Text Click this to open the Web tab of the Format Picture dialog box, and then type the alternative text that you want.
After you publish your publication to the Web, you can see the alternative text when you rest your pointer on the picture.