Question for photography buffs

[mjzee]

I'm listening now to Dexter Gordon's American Classic.  The back cover has a picture of Dex looking at the Statue of Liberty.  It appears to have been taken on site (probably at a park on the Jersey side).  Yet, even though taken outdoors, the picture seems to show a shadow (caused by the camera's flash) on Dex's right side.  It's as if he was photographed in front of a wall, but he appears to be in the open air.  Any idea how this effect was achieved?

[BFrank]

This happens when you use a flash and set the shutter speed slower than the manufacturer's recommended "sync" speed. That's not really a shadow, but Dexter himself recorded on film a split second after the flash shut off.

[mjzee]

Neat effect; thanks!