My pop says that at the first (real) flag raising, every Marine looked up and cheered, and all the ships (there were MANY!) hit their whistles. There was much fighting still to do so they went back to work. The Lowenthal flag was raised to no notice. This is about all he would volunteer about his 3 weeks on Iwo.
Whether there were 1 or two raisings, the effect on morale was tremendous.