When Gertie is checking into the hotel and introductions are being made, the moving boom microphone dips well into the top of the scene.
Before Gertie leaves her hotel room to go see the fortune teller, a moving shadow of the boom microphone is visible across the top of the door to her room.
"Big Boy" is referred to as a Marine more than once, but on the left shoulder of his uniform is a patch for the Eighth U.S. Army.