Possibly the AS-33/34 the missile developed from the AS-30 that was earmarked for TSR2. The design was sold off to West Germany to become the basis of the Kormorran whilst Aerospatiale revamped the design for both the AS-37 Martel and AS-39 Exocet.
I would guess the artist was supposed to do Martel and used the AS-34 design as its basis.
There was a proposal to fit Red Top to the Phantom to give it a longer range IR missile than Sidewinder for use in ECM environments; it was not proceeded with due to the high cost of Red Top; £18,000 as opposed to approximately £6,000 for a Sparrow 6(b) and £3,900 for a Sidewinder.
Red Top's performance was assessed as similar to Sparrow in a non-ECM environment.