To use the Pictures on your Item in the Description you can either use the Picture tag, or PictureURL tags and just include the number of the Item Picture. [[PictureURL1]], [[PictureURL2]] etc.
More from the User’s Guide:
The [[PictureX]] tags get resolved to a full link to your images on the web including the <IMG> tag and all of its settings . If, however, you want to control the aspects of the display of your image, you can use the [[PictureURLX]] (where X is a number from 1 to 12) tags in conjunction with your own <IMG> tag. The [[PictureURLX]] tag will simply resolve to the URL of the picture (something like “https://www.sixbitsoftware.com/mypic1.jpg”).
John Manning, Senior Developer