Can you spot the mistake in this One Piece drawing?

Here is a One Piece image published in a recent issue of Weekly Shonen Jump. If you watch well the picture, you will notice that there is something wrong. Try spotting it.

Noticed anything? I give you a clue: look at Usopp’s bike.

The last image, a drawing made by the designer Takumi, has the solution.

Now, have you spotted it ?  ^ ^