So even though it didn't appear like it at first glance, he was trapped. He couldn't get out and he couldn't communicate his need for assistance. He just had to wait for someone to return to help him. He could only observe the outside world from behind the window.
While there were many real life incidences similar to this one (even though we're long past that now), this snippet pictures this wretched disease as a whole. It serves a reminder to me to love the helpless, as Jesus did. And not just those with Alzheimer's; helplessness comes in many different forms, sometimes appearing from the outside that all is well.