Often Demo and Real accounts are supplied from different feeds. Also the probability for an order to be filled is smaller for a real account than for a demo (where it's almost 100%), and the fills happen at slightly different prices to what you wanted on the demo. Thus your EA optimization on a Demo usually has much more opened/closed trades than it would be in reality.... In short: even if you send signals from your Demo to your Real the results for them will be very different...

The same consideration should be applied to when you send a signal from your Real account of one broker to your Real account of another broker. The result will not be identical. I have an extensive data for that (1 year), where I used the same strategy through a quality master/slave technology on two Real accounts of two different brokers... Now sit down, please: profit-result was ~400% different!!!!