From Bob Dearborn's The Olde Disc Jockey's Almanac...
May 13, 1969…The Beatles, now with beards and long hair, met at EMI House in London to replicate the cover of their first album for the cover of their current album project, "Get Back." When that project evolved into "Let It Be," the photograph was put aside until its eventual use for the cover of the compilation release, "The Beatles 1967-1970," nicknamed the "blue album."
Everyone knows these pictures today...