Seeing these images, couldn't someone make a profit out of the price difference? By arbitaging.
Arbitraging is profitable only if the price difference is greater than the tradeing fees. That is one reason why the Chinese exchanges have such high volumes, and have very similar prices: one can do arbitrage even on tiny differences in price.
On the other hand, one does not need to actually move dollars or bitcoins instantaneously to do arbitrage between two exchanges. To do arbitrage one should buy at A and sell at B when the price is lower at A, and do the reverse when the price is lower ar B. If one has substantial BTC and dollar funds on both exchanges, one could alternate between these trades in such a way that the four accounts remain mostly balanced in the long run. If they become unbalanced, one can transfer BTC and/or dollars to rebalance them, but those transfers can be slow.
Someone claimed that Bitcoin arbitragers may use Litecoin to transfer funds between exchanges, because of its faster confirmation time.