The TV has mounting hardware attached that fits into keyhole slots which are screwed into the cabinet. It can can be removed by sliding it up and then pulling it forward. You should then be able to see if the cable running from the box is attached to HDMI2.
I got tired of needing to physically connect my iPad anytime I wanted to watch something. I replaced the main TV with a Samsung smart TV that came with streaming apps and the ability to mirror my iPad’s screen. It is much more convenient.
I set the old TV outside my RV with a sign “FREE works great”. It was gone before we finished dinner.