I saw this post 2-3 days ago. Here Oda sensei explained why he drew that!
But apart from that I think there may be a deeper reason why he did that.
I think Oda sensei hinted that the story of Dressrosa Arc is inspired by Alabasta Arc.
We know he does that a lot. But if that is true then he is insane. Writing a story inspired by his own story... is on a different level, I think. In the end we see that these two stories has different viewpoint, nature and ambition of Crocodile and Doflamingo are different and a lot of things are also different (although the two arcs share a lot of similarities).