You notice the box's front juts out a bit, and pushing on it, the portrait's panels open to reveal a deep dark winding way down through the house. Before you can consider your options properly, you hear a loud roar from behind the locked door, with heavy footsteps and an unfriendly person's shouts following it. Loud attempts to break the door down are made, and sound like they will be successful soon. Since every other option would bring you closer to whoever and whatever is trying to get in, you clearly only have two options:
escape down the lion hatch, or
stay and face whatever's coming.