Richard Alpert returns, checks out baby Locke

Here, we see Emily Locke, her mother and the nurse standing next to baby John Locke. The nurse tells them that he is being referred to by the other nurses as the "miracle baby" due to his being the youngest premature baby to survive at the hospital. He also had infections and pneumonia and fought them off. Before she can hold John, Emily runs out of the room saying, "I can't do this." Emily's mother asks about adoption as she starts to light a cigarette before being told by the nurse that she can't smoke there.

Then comes the best part of the scene. Richard Alpert returns for the first time since season 3 (Cane was good but I'm glad it's gone so Nestor Carbonell could return to Lost). He appears at the window looking in on baby Locke. The nurse asks Emily's mother if he's the father and she says she's doesn't know who he is. Again, Richard Alpert appears to be the same age as every other appearance, even though it's the 1950s this time.

Why was Alpert watching Locke and how did he seem to know that Locke was special from his birth?