I haven't received my 2003 Member Guidebook in Texas. My DS (the doctor) and his DD (his little princess) are on page 76 in the 2002 Member Guidebook. The photo (a 4th place winner in the member photo contest) was taken by my DDIL. You might be interested to know that Disney enhanced the photo a little by adding clouds in the sky. It actually was a cool, cloudless, overcast morning when the picture was taken. Oh, did I mention that my page 76 is worn out? When we get out 2003 guidebook it will never replace our 2002...
Based on the photo credits (on the inside back cover), I'd say that the people in the guidebook are members. Why would they list the location/home if they were models? Not the best photos or the best-looking people at times (again not professional photos or models), but DVC'ers just like you and me.
I do think that I'm gonna sit right down and write DVC, and include some photos of my family vacation. I'd like to see them in the Letters From Home in VM or the guidebook next time (I'm the picture-taker too, Pluto4).