It would appear that these men (and woman) are looking at an aerial show. The man in the middle with the radio is possibly in contact with the pilot. However, the caption for the photograph reads below:
This photograph shows members of the Senate military affairs committee at a demonstration of the improved radiotelephone. Col. C. C. Culber [sic] is telephoning orders. Senator Francis E. Warren is listening in, next to him is Maj. Maurice R. Connelly, a former member of Congress, and on the left, Senator John W. Weeks. Back of Colonel Culver is Maj. Gen. William L. Kenly, chief of aeronautics. Copyright, Harris & Ewing.
This is such a great shot.