This isn't a definitive answer, but the album's lyrical content suggests existential themes of reaching out for some kind of genuine human connection within contexts that are dehumanized, depersonalized and faked. The image resonates with these same themes by presenting a glossy image of success --a deal between two wealthy power-brokers, backstage at a movie studio --and subverting it with the fact that one person is literally on fire, but both are pretending not to notice.
The concept behind "Welcome to the Machine" and "Have a Cigar" suggested the use of a handshake (an often empty gesture)
The album's cover images were photographed by Aubrey 'Po' Powell, Storm's partner at the Pink Floyd design studio Hipgnosis and was inspired by the idea that people tend to conceal their true feelings, for fear of "getting burned", and thus two businessmen were pictured shaking hands, one man on fire. "Getting burned" was also a common phrase in the music industry, used often by artists denied royalty payments. Two stuntmen were used (Ronnie Rondell and Danny Rogers), one dressed in a fire-retardant suit covered by a business suit. His head was protected by a hood, underneath a wig. The photograph was taken at the Warner Bros. studios in Los Angeles. Initially the wind was blowing in the wrong direction, and the flames were forced into Rondell's face, burning his moustache. The two stuntmen changed positions, and the image was later reversed.
Straight from Powell, Storm, Roger, and David. The industry burned them and other artists. They had no intention of being commercial they only wanted to make music. Listen to the lyrics of Have a Cigar and pay attention. Hence Welcome to the Machine. The industry was just a machine cranking out top selling albums. Once you quit or fell short bye bye.