I placed names over each of the individuals in the picture. At this time, the First Presidency consisted of Lorenzo Snow, George Q. Cannon, and Joseph F. Smith.
If any of the transcripts from the Reed Smoot hearing have been reviewed, you'll recognize many of these names from the photograph. The two that gave the Senate committee the most trouble are John W. Taylor (son of former president John Taylor) and Matthias F. Cowley. Both of these gentlemen evaded the law for a number of years to avoid testifying before the Senate committee.
One of the reaons I like this picture is because it has 3 sons of former presidents of the church (Brigham Young, Jr., John W. Taylor, and Abraham O. Woodruff), one current president (Lorenzo Snow) and 2 future presidents (Joseph F. Smith and Heber J. Grant) of the church.