Break the statues if you want - there's gold in some of them. Send one minion to grab the spoke in the middle of the room and put it back on to the broken mechanism (#1) - now you can open the door and set Velvet... free? Watch the scene and you'll see what's going on here: now choose if you stay with Rose or dump her for Velvet. We're going the normal evil option so at that point you stay by Rose. Now you've learnt an important thing: Rose can upgrade your minions in the tower: browns for free, but for the blues you have to pay 5000 gold. If you want to see the effects, go to your tower private chambers. You can also get a new carpet or some statues on the occasion.