The rod connected to the "leg" of the hatch at right-center is part of the
hatch actuator assembly.
Unlike the Mercury and Apollo spacecraft, the Gemini spacecraft did not use a
launch escape tower; rather, it was equipped with jet fighter-style ejection
seats. In an emergency, a pyrotechnic system would push the rod upward to open
the hatches, making way for the ejection seat.
The top part of the command pilot's seat is visible, as well as a grey stowage
container (which would be above the commander's right shoulder).