3rd camera from the left is an RB Graflex 4"x5"
5th from left is an Eastman Kodak 5"x7"
7th from left is the back side of a Graflex 5"x7"
8th from left is a Graflex 5"x7"
It would appear that this is the white house Press Corps circa 1921
Note that they are in the middle of the croquet court [Wicket in front of pic]
The Cameras on tripods all appear to be early motion picture cameras.
The onse being held by had appear to be early Graphlex [forerunner of the Speed Graphic] cameras....commonly in use by the press.