Perhaps ideally it would not, but there are limits to any mechanical device. The derailleur has a tension spring to pull it back and keep tension on the chain, but there is too much slack here, so it is all the way back with the chain slack. I doubt the chain is too long unless you just installed it. If it was fine before and all of a sudden it isn't, then something we can't see is out of place or broken. Like the chain going around the front chainwheel.