Oh well... They were hippies, free love, nature, all that bullshit. What's funniest is that before taking this picture they recorded some of the crappiest music in either ones discography and fucked for the first time right after finishing the shoot. I'm still not sure if it's corny or G.O.D.ly.
Lennon wryly commented that the uproar seemed to have less to do with the explicit nudity, and more to do with the fact that the pair were rather unattractive (and the photo unflattering; Lennon described it later as a picture of "two slightly overweight ex-junkies").
Anyway Yoko had teh stupidest ideas at that time, like that protest over I don't know what, when John was lying naked in the middle of New York among his own shit.