This is a similar shot to the one that I took as we departed Capri, but with the addition of a building on the left, and a plane in the centre.

From the position of the building I would guess that I was looking roughly north east here, which is indeed the direction of the airport. The airport itself is less than 5km away from the port. The runways are 08 and 26, so if this one is outbound from runway 26 then (a) it must have climbed like the clappers (which is possible) and (b) it must have swung a bit to the south after that.

Both of those are possible. Since Napoli is hemmed into the coast, the airport is a lot closer to residential regions than is the case for, say, Tullamarine in Melbourne. Noise abatement (by getting aircraft as high as possible, as fast as possible) is therefore very important.