It's actually impossible to create a "complex" item with text + images. It would be really useful for character and Handouts items. Actually for a character, you can only choose 1 avatar picture; (Another can be used for the token, but isn't displayed on the Character window, except in edit mode). You can link handouts into Bio & Info text field, but it will be a clickable text link which open the handout in a popup window, not a picture directly . displayed. Handouts are just 1 single picture with simple text note. I dream of "pages" layouts, with text + pictures (linked files from library), like an html page.