Yes, you are seeing that right. Those are 55 gallon drums falling toward Motoyama Airfield #2 (Central Field). During the 7th Air Force bombing campaign of Iwo Jima, B-24J Liberators flew a number of missions in which they dropped 55 gallon drums filled with naplam in an attempt to burn off foliage leading up to the invasion.

The official caption for the photo reads: “DRUM BOMBS – Seven of the 55-gallon drum fire bombs released by U.S. Army 7th Air Force just above Airstrip No. 2 on Iwo Jima on Feb. 1, 1945 head for the wooded area near the boat basin where the invasion took place. Chemical officers recommended heavy strikes of several thousand of the drum bombs to prelude the Iwo invasion. The bombs are fitted with plywood fins designed to take the place of unavailable metal fins.”

It looks as if the fins provided stability for the 55 gallon drums as they plummet uniformly to their intended target.

This photo also provides a nice diorama idea. Several aftermarket manufacturers produce resin 55 gallon drums for dioramas in both 1/72nd and 1/48 scales. It would be a neat diorama showing on Consolidated B-24J Liberator being loaded with the 55 gallon drum bombs.