It seems that texture detection is for NN the simplest and easiest way to recognize objects. I guess early animal vision system used to work this way. Then predators and prey developed camouflage and mimicry, to fool texture detection NNs. So there was strong evolutionary pressure to recognize shapes, which is much harder task, but essential for survival. Probably that's why people see in the picture a cat (predator) and ConvNet recognizes most obvious thing (elephant) in terms of statistics.