Final answer:
The U.S. flag should be placed on the observer's left with its staff in front of the other flag's staff when displayed on crossed staffs against a wall.
Step-by-step explanation:
The U.S. flag, when displayed with another flag against a wall on crossed staffs, should follow specific guidelines according to United States flag etiquette. In such a display, the U.S. flag should be on the observer's left (the flag's own right), and its staff should be in front of (or above) the staff of the other flag. This means that when correctly displayed, the answer to the question is: The U.S. flag should be on the right (from the flag's perspective, which is the observer's left) and its staff should be on the left of the staff of the other flag when the flags are viewed from the front.