No it's not normal, the gallery implementation is quite wonky indeed. Think of the gallery scenes as a playlist that plays them in a specific order. If one ends, the next starts playing. The gallery screen you see at the end of a scene is kind of "fake", you're still in gallery mode, which becomes apparent as soon as you close the gallery. Pressing ESC enough times should get you out of this. If you're on Android then though luck; it's probably best to restart the game if that happens.