Hi Battery Rocks,
It sounds like a commendation which would be similar to a certificate recognising meritous service - good work over and above that expected.
I would suggest that it was awarded by the C in C - the Commander in Chief MEAF (Middle East Air Force). C in C MEAF would be the big cheese of all Air Force personnel in theatre at that time. At the time your relative was in the Middle East and was awarded the commendation, the C in C was Air Chief Marshal Sir Hubert Patch.
If you can get the service records of that individual, you may well find a copy of the commendation in the personal file.
Thudders