that might have been me commenting in dreamwidth_meta. i definitely think "text equivalent"/"text alternative"/"text replacement" would be a better name for the field, because that's what alt attributes are supposed to be, though in some cases that may happen to be a description of the image. (for that matter, maybe "description" would be a better name for the "comment" field...) it would also be really useful if there were a direct link to guidelines for writing text alternatives on the icon management page.