Any idea how to get a picture from this?

This is a black and white 5.5inch portable tv (added GameCube picture for scale). It takes 8 D batteries, or can be powered via cable.

The radio works, and screen powers on. It looks like it has rca inputs on the back. However I am unable to get sound / picture using said cables. I am not sure how to switch to av mode.

Are these actually rca inputs? I couldn't find a manual online. I've had this tv since I was a kid, I believe I only used it for radio back then.