And it may be that the vase was created by the player.
DM: "You enter the princess's chamber, it is luxuriously furnished."
Player: "Are there any vases in the room?"
DM [making something up]: "yes, there is a vase of flowers on the desk."
Player: "I walk over, smash the vase, and yell angrily at the princess."
In my game, it might go further:
DM: "You enter the princess's chamber, it is luxuriously furnished."
Player: "I walk over, smash an ornate vase that is sitting on her desk, and yell angrily at the princess."
I love for players to add story enriching details. For example, the exchange below (more or less; I didn't record it or anything) happened between me and a Grade 9 player in her third game. The set-up is that the characters were in the pirate town Darktow, looking for supplies and information, and her character, who had previously lived in Darktow, had walked into a tavern.
Player: Do I see anyone that I recognize?
Me: You tell me. [at this point, I am trying to see how far the player is comfortable going with improvising a scenario; I'm ready to step in]
Player: Ummm...yeah, I see my sister sitting in a corner.
Me: Are you on good terms?
Player: Uh...no, she's really mad at me.
Me: How come?
Student: Uh...I'm not sure...can you?
Me: She glances up and sees you staring at her, and immediately her expression shifts into a glare. What do you want to do?
Student: I guess I go over to her table.
Me: As you pull up a chair she hisses, "How could you leave me in this place..." [and we carried on from there.]
At that point we improvised the rest of the encounter, working out that her sister had been left behind when the character had to flee due to a dispute with the local boss, and now was working to pay off the character's debt. This gave the player an opportunity to pay the debt off herself, freeing her sister, who then grudgingly supplied the information the character was seeking. None of this was planned, except for the information that I wanted the players to get somehow (I had other means of getting it to the players if necessary, but preferred to let them devise a stratagem).
In this process the player did a ton of world-building connected not just to her character's backstory but to Darktow itself. And I honour that by letting the world change to fit the players' contributions. I've had major campaign arcs come completely out of player additions to the story, happening mid-play. Is this an unusual approach?
For me, I love it because I get to be as entertained by the story as my players - I had no idea that character had a sister, or a whole family drama around a pirate town. The player, in her third game, supplied the crucial details of 1. sister 2. bad blood and 3. debt. This made for a really fun sub-plot that ultimately drove the main story forward and was so much better than anything I had planned out!