In the 1939 flashback scene, such as when the Tower gets hit by lightning, what seems to be the Capitol Records Building can be seen. The Capitol Tower did not exist at the time when Sally Shine died until it was completed in 1956.
When Anna is waiting outside the hotel for her Uncle Buzzy and Carolyn Crossland/Claire Poulee to return the main door can be seen in the background open. But when she decides to enter alone she is then seen opening the door herself. A few minutes later when she is seen looking for personal effects of the ghosts behind the reception desk, the door is open in the background but when she runs from her encounter with the ghosts it's closed then open again in a matter of seconds.