I saw that coming a mile away

As soon as Anna picked up that stool, I knew what was going to happen.  What I can't figure out though is the purpose of that whole thing if she was going to come to with nothing happening.  That could have been a very tragic situation.  Maybe it'll make her think she should bring Sydney back home because she is there all alone.

BTW, didn't that look a lot like the Horton cabin?  Except for the window in the door.  But, we heard sirens outside and I don't think there are any cars on the island.