If you have installed both the LispWorks images, for native Mac OS X and for X11/Motif, you will want to configure two images.
If necessary your Lisp configuration and initialization files can run code for one image or the other by conditionalization on the feature :cocoa. The native Mac OS X LispWorks image has :cocoa on
*features*
while the X11/Motif LispWorks image does not.