An image is a image object stored in client, not X server, memory.
A pixmap, on the other hand, is a image object stored in the X-server.
See GDK2.Image and GDK2.Pixmap.
GTK2.Image("tornado_nguyen_big.jpg");
Properties:
string file
string icon-name
icon-set
int icon-size
GDK2.Image image
GDK2.Pixmap mask
GDK2.Pixbuf pixbuf
GDK2.PixbufAnimation pixbuf-animation
int pixel-size
GDK2.Pixmap pixmap
string stock
int storage-type IMAGE_ANIMATION , IMAGE_EMPTY , IMAGE_ICON_NAME , IMAGE_ICON_SET , IMAGE_IMAGE , IMAGE_PIXBUF , IMAGE_PIXMAP and IMAGE_STOCK