The show looked back over 10 years of her career, and was billed as "A show of unfinished paintings and sculpture". It ran until 27 October 1971.
This Is Not Here had been commissioned in the week before Lennon and Ono left England. With less than a month to prepare, Ono invited her husband to participate as 'guest artist', and also asked friends in the art and music world for contributions.
This Is Not Here was a slogan from a sign which the couple had placed outside their Tittenhurst Park home in Ascot, England. While the exhibition was primarily a retrospective, it did contain some new material, including a looped screening of their film Clock.
One room, devoted to 'Water Pieces', contained items donated by Ono's friends. Each of the pieces was designed to be filled with water; Lennon had made a small fish tank containing a pink sponge, which was titled Napoleon's Bladder.
The exhibition catalogue took the form of a collage in the shape of a newspaper, and was compiled by Lennon and Peter Bendry. The back cover featured a sequence of photographs of Lennon and Ono which morphed their faces from one to another. The sequence was later used on the labels for Happy Xmas (War Is Over) and Some Time In New York City.
Guests for the opening night included Ringo Starr and his wife Maureen Starkey, Allen Klein, Phil Spector, Bob Dylan, Andy Warhol, Frank Zappa, Spike Milligan, Jack Nicholson, Dick Cavett, John Cage and Dennis Hopper. Lennon gave all visitors a silver necklace to mark the occasion.