Can someone explain how this pic was taken?

[jmc-man]

For you doubting thomas's and particularly for SheenGimp,

Try THIS

or

This

and an explanation from Sam Chui himself ( all available on the other website)

We are flying on a published LAX shoreline corridor route at 3500 feet, with most planes departing LAX at quite a distance at 500 feet or so and restricted to 1000 feet...so in most danger case you have 2500 feet between you, and of course you're cleared by the LAX control from long beach or Santa Monica/Hawthorne....Just let your camera and lens (and the brain) do all the work. All about is LUCK, anyone can fly over LAX on the published track at anytime, but to catch a heavy plane departure is something you can't control.

and finally , a discussion

here