Mulligan Question

[Absoltrainer]

When an opponent mulligans, they reveal their hand to the other player to show their lack of basic Pokemon. During this time, am I allowed to view and read specific cards in their revealed hand? Or am I supposed to verify the absence of basics and nothing more? I asked several players and judges and was unable to receive a confident consistent answer. My personal guess would be yes, the cards are revealed and therefore public knowledge at the time of mulligan.

Thank you in advance.

 

[PokePop]

You may, as long as it is done in a reasonable time.
The game action is supposed to be completed within a few seconds, not minutes.