You gotta be kidding ???
Well that's gotta be the most chubby 737 ever built
An easy way to see the differences is by looking at the nose. The 737 has a very pointy nose, while the'busses tends to be more round, although it's a little hard to see that from that particular angle.
The engines are mounted very far from the leading edge, comparing to a 737, also the A310 has more distinct external hinges for the flaps. The rear APU exhaust extends too far from the vertical fin, than a 737's...the list goes on