Alternative text provides the textual equivalent of an image to the web page. The description you write should be short and concise, but accurately describe the image content. Implementing alternative text allows screen readers to describe an image that would otherwise be skipped over to those with visual or other cognitive impairments. For this reason it is required that all images must implement proper alternative text.
To add alternative text to an image follow these procedures:
1. Click on the Image (#1) button below the WYSIWYG editor.
2. Select the image thumbnail (#1), then add the alternative text where it says Image Description (#2).
3. Insert the image and save the article. It is okay that you do not see the alternative text, it will only show up if disable images in your browser.