The photo comes from the Twitter account of an employee at Veister.com, who posted it because - well, we don't know why he posted it. However, Viester.com sells electronics accessories.
The photo says it is an iPhone 5 sync / charging cable. Naturally, we don't know this for sure, but it very much resembles what has been rumored to be the new dock connector design.
The size shows us that Apple could have, if it so desired, chosen to use the now industry standard microUSB connector. Ah, but that wouldn't be Apple's style, now would it? It would also mean you wouldn't be forced to buy Apple cables (at least until the cables are cloned and show up on eBay for $0.50 or less.
By zooming in on the image, we can see it's the same nine-pin design we've seen recently.
Apple is rumored to be launching the iPhone 5 on Sept. 12, releasing it to retail on Sept. 21. At the same launch event, Apple is expected to also introduce a smaller-sized iPad mini, a new iPod nano, and a new iPod touch. That new "new iPad" is also a possibility.