Push aggressively to hold the airspeed; left to its own devices the airspeed will soon decrease rapidly. The glider is in roughly a normal glide attitude (or a bit more nose-down from that) but way above trim speed, so this is not a steady-state situation in any way, shape, or form. Left alone, the nose will rise dramatically as the flight path curves upward, and the airspeed will bleed away to far below trim speed-- you may even get a stall break.

S