widget-image-insert

widget-image-insert is a compiled Lisp function in `wid-edit.el'.

(widget-image-insert WIDGET TAG IMAGE &optional DOWN INACTIVE)

In WIDGET, insert the text TAG or, if supported, IMAGE.
IMAGE should either be an image or an image file name sans extension
(xpm, xbm, gif, jpg, or png) located in `widget-image-directory'.

Optional arguments DOWN and INACTIVE are used instead of IMAGE when the
button is pressed or inactive, respectively. These are currently ignored.