Magnificent photo of a very scarce aircraft - thanks for posting this

Love it! Never seen one of these. What is the rope he's pulling? Tow release?

LOL! The FAA registration record says it has a "reciprocating" engine, but lists it as a glider and engine type as "unknown."

Piper, Aeronca and Taylorcraft all built gliders for the Army, converted from their liaison planes already in production.
What isn't very visible in this photo is that they had 3 seats, 2 in the normal positions under the wing, and a third up front for the instructor.
The pilot here is operating the wing spoilers with the overhead rope, the tow release was operated from a lever on the left sidewall of the cockpit.

Since these gliders were initially converted from powered planes, most were re-converted back to power after the war.
This glider is owned by the Western Antique Aeroplane and Automobile Museum in Hood River OR.
Nice photo of a rare plane, thank you for posting it.

http://www.fiddlersgreen.net/models/aircraft/Piper-TG8.html

My Father was offered to be an Army Air Corp Glider pilot in WWII. He asked a very important question: "What do I do when it lands." The answer made him become a flight engineer on B-17's an B-29's. The answer Dad got was: "You pick up your rifle and follow the troops."

Great to see a TG-6 flying.

"LOL! The FAA registration record says it has a "reciprocating" engine, but lists it as a glider and engine type as "unknown." "

The registration anomoly may be due to the original aircraft being modifed from a surplus L-2 (DC-65) to a TG-6 configuration. Hence the NX number.

The upper cord is most likely to actuate the spoilers. That is the only control up there.