When Henry is doing the laundry in the basement you can clearly see how light it is through the window. When he goes back upstairs, it is suddenly dark.
I believe some time has elapsed since he started the laundry... He started with his pitching fantasy when it was light out, then he would have had to start the laundry. Also, it could have been somewhere close to dusk, so not too much time would have had to pass before he could walk upstairs and it would be dark. This is just what I think.