It appears that Mark's neighbor can see into 2 windows on the side of his duplex facing her. However, an exterior shot shows high hedges growing between the two buildings and covering any lower level windows.
When Mark is leaving for work and speaks to Mrs. Selvig as she's blow drying her front steps, all four snow-covered garbage and recycling cans for their two units are pushed up against the hedge. When Mrs. Selvig is leaving for work a little while later, the two blue cans are both up at the street, still covered in snow.
At 53:32, a paramedic calls out, "Whoa! Whoa, whoa, whoa, he's down, he's down!" prematurely, about 4 seconds before a character collapses to the ground.