I spent 6 weeks temporary duty at Mauripur in '56 as RHS for the Air Attache's Anson. Never got airborne and lounged about in the Mess most days. Outings to Karachi were an extraordinary mix - unbelievably awful conditions for hundreds of thousands of post-Partition refugees on the mud flats and the most luxurious cinema I've ever been in, in the city. The rupee was worthless such that importing Mess supplies was conducted by bartering leather goods. Customs check on arrival (APCSS Valetta), was simplified by a bottle of Gordon's left in the rear seat-back pocket. Startled awakening on the first morning by a turban-ed apparition bearing a cut-throat razor - morning shave in bed with essential cup of chi! As to the OP's photo, I would guess (with little evidence) that the group were the BOAC(?) staging post staff 'letting off steam'. Limited social activity otherwise.