The tires on the left are identical. Literally. It's the same photo of one tire, rotated 180-degrees, complete with drop-shadow on the top.
The point does stand, that some tire styles are asymmetric, but not directional, so all tires in the line are identical, regardless of position, although they should be mounted in such a way that certain features of the tread block are to the outside/inside, but it doesn't matter which rim is located where on the vehicle as long as they're all mounted correctly (they may be rotated in a cross-pattern). I believe that's what KayGee is getting at, correct? Firestone Firehawk GT Pursuits are a good example.
Then you have directional, symmetric tires, all identical, but they may only be rotated on a particular side, but it doesn't matter which side a given tire is originally mounted on as long as the arrow is pointing in the direction of rotation; sides could even be safely swapped for the purpose of rotating tires, as long as the tires are remounted on a wheel in the reverse direction. Goodyear UltraGrip X-Ice are an example of these.
It's largely the same with asymmetric, directional tires, only they're specific to the side of the vehicle they're mounted on and cannot be reversed on rims to change sides, only moved forward or back, as seen in Ronxlt's link.