It was taken to commemorate an extension to the existing three-movie 1964 contract between MGM and the Colonel, adding three more films.
The standee was created for a “Happy Birthday” celebration for Howard Strickling, the MGM studio fixer and liaison and was taken near Elvis’ Californian home whilst he was filming in Hollywood

Contract with MGM in December 1964
Parker completed a new agreement with MGM for three more pictures. It called for Elvis to receive $1 million for the first film. A quarter of that was to be paid to Elvis at $1,000 a week over five years. For the other two movies, Elvis was to receive $750,000 each. In addition, the contract gave Elvis 40% of the profits from all three films. Made under this pact were Harum Scarum (1965), Spinout (1966), and Double Trouble (1967).
Contract with MGM in January 1966
Although only one picture had been made under the December 1964 contract, the MGM agreement was extended to include four more films. Elvis’ fee was set at $850,000 for each film with profit sharing increased to 50%. Titles produced under this agreement were Speedway (1967), Stay Away, Joe (1968), Live a Little, Love a Little (1968), and The Trouble With Girls (1968).