This addon from brykrys adds an icon to the reference tooltip and the popup tooltips.
Author: brykrys
Adds an icon to the reference tooltip (from clicking on an item link in chat) and the popup tooltips (when mousing over an item).
Icons can be displayed in a small frame to the side of the tooltip, inside the tooltip (near the top right corner), or used as a background for the tooltip.
Only works for Items (not recipe links).
Configuration:
TooltipItemIcon uses slash commands to change modes, to enable/disable certain tooltips, and to change the location of the icon frame around the tooltip. These are documented in the included commands.txt file, but here are some examples:
/ttii inside {switch to Inside mode}
/ttii gametooltip off {disables the icon for the popup tooltip}
/ttii gametooltip lefttop {moves the icon for the popup tooltip to the left side}
/ttii reset {reset all settings to the defaults}
Compatability:
Should be compatible with any language version of WoW.
Compatible with Link Wrangler and some other Tooltip AddOns. (Some of these are able to display icons for spells too).