What is the key for, Doflamingo is holding in chapter 752?


As far as I recall, the only locks mentioned during the [Dressrosa
Arc](http://onepiece.wikia.com/wiki/Dressrosa_Arc) are:

  * The lock to the [SMILE factory](http://onepiece.wikia.com/wiki/SMILE_Factory)
  * The lock of Law's handcuffs

Though, in **chapter 747** Doflamingo destroys the key to the factory.

[![enter image description
here!](https://i.stack.imgur.com/F8NHhm.png)](https://i.stack.imgur.com/F8NHh.png)

And in **chapter 750** , we can see Viola holding the key to Law's handcuffs.

[![enter image description
here!](https://i.stack.imgur.com/K9wzqm.png)](https://i.stack.imgur.com/K9wzq.png)

So what is the key, Doflamingo is holding in **chapter 752** , for?

[![enter image description
here!](https://i.stack.imgur.com/eYNeim.png)](https://i.stack.imgur.com/eYNei.png)




I think as far as we know, you can't tell for sure if it's one of these two
possibilities.

But if I compare the key to the SMILE Factory with the last one you can't see
anything similar. So I think it's **not another key to the Factory.**

![enter image description here](https://i.stack.imgur.com/k1zC5.png) ![enter
image description here](https://i.stack.imgur.com/wipsz.png)

Even though the other is much smaller on the picture, if you zoom in, you can
see that the **key for Law's chain is round.** On the other side
**Doflamingo's key has the shape of a heart.**

Another point is, that the **left one has a little hook...**

![enter image description here](https://i.stack.imgur.com/YnYgu.png) ![enter
image description here](https://i.stack.imgur.com/wipsz.png)

So I think this is just speculation, but I think even if it's one of these two
options it would be the key to Law's chain.

In my opinion, it's a key to something new, maybe even more important.

