‘Push’, means you use your musscles/strenghts, like in the case of pushing the ‘big business’ in toilet.

Okay, why I ask this? Coz Ian and Isabel are the completely opposite.

When they are doing big business…

Ian would narrow his eyes while he was pushing, leaving just a line for seeing.

Isabel, on the other hand, widen her eyes like nearly poped out! Very cute… I think her eyes are biggest when she is doing her big business.