My reaction was a like Michael's.
I knew a lot of long haired guys who fiddled with guitars in bed wearing blue jeans and a blue "workshirt". (err....I was one myself).
If it wasn't the "celebrity" it wouldn't be considered much of a photo.
But perhaps it was mutually beneficial. It demonstrated that Liebovitz had "access" to a celeb in even the most informal settings. And it made many of Lennon's guitar-fiddling fans think: "Hey, this dude's just like me!"
Had to be a career enhancer for both....