When young James Dean is lying in bed he is on his back with his left hand beside his head when his mothers enters the room. In the next shot his is lying on his left side with both hands in front of his head.
The label on the box James Dean sends, reads "Santa Monica, CA". In the late forties/early fifties it would have read "Santa Monica, Calif." because the two-letter state abbreviations weren't used yet.
James Dean's mother seems to have been treated by a mechanical ventilator in what would have been 1940. The first positive pressure ventilators were not available until the 1950s. If mechanically ventilated, she would have been in a negative pressure "iron lung" as was used for polio victims of that era.