The picture was colorized by a Stuart Humphreys from Babelcolour. It is a picture of British War workers relaxing on a beach in 1943. So if it's World War II, how does the man in the center have what appears to be a cell phone ?
Some have speculated that it could be a hand held calculator, but they weren't invented untill 1966 and a basic patent for miniature electronic calculators wasn't issued till 1974, to Texas Instruments.
Time Travel: A New Perspective
Scattered throughout the world are objects that could not possibly belong to the time period in which they were found. A human footprint contemporary with the dinosaurs? The skeletal remains of men and women long before humanity appeared on the planet? This text shows how time travel is not only theoretically possible, but that the future generations may already be engaged in it.