User blog comment:Xilinoc/Ch. 850 - Oda's Still Got It/@comment-24850639-20161222133546/@comment-53539-20161222213146

Ya know, if she's such a great actor, why reveal herself to Luffy, Nami and Reiju now? This. This one small misstep on her part is my sole reason for still believing in her.

Maybe she isn't such a great actor.

Remember how Kuro was unable to keep it tied up when looking at a crescent moon?

Sometimes a persons true nature good or bad cracks at the seams as a person an't maintain it ll the time and is frustrated by their stage act. They need to find a moment to let some of their true nature out and relax. It might not be a sign of confidence but a need for Pudding to be herself.

She, however, no doubt thinks she can relax now since everything is going according to plan. If Sanji does not go ahead, or Sanji does, the situation is at a point where she likely as well doesn't care less what happens. The entire Germa army is where it needs to be, the straw Hats are "captured", the Vinsmoke's think they've got a good deal and are letting their guards down... Saying that... They too have have their own plans that are only a step down from Mom's.