A slightly different vase

Exploration Stage: Hidden Row
From: Lady
Description: It seems that my mansion has been visited by a...well...newcomer. But nothing that belongs to me is missing. On the contrary, there seems to be more stuff. Someone left an elegant bouquet holder. I was going to give it to the detective, but I think I dropped it somewhere... can you help me find it?
Completed: It's a very beautiful and elegant bouquet holder, but if you put flowers in it, they die quickly. Besides, ever since I found it, I have been having a lot of dark thoughts. I would never have done that before. Whoever left it must be good at putting people under psychological pressure.