Gintoki was thrown in prison after being framed, and while he's made an enemy of the warden, he's managed to become the boss of the prisoners.  With his underling Shachi in tow, Gintoki skips his menial labor duties to search the warden's room for anything incriminating.  Understanding that the punishment will be fatal if they are caught, Gintoki disguises himself by putting on pajamas...
That would explain why they only made small talk.
Eso explicaría por qué hablaban de cosas sin sentido.
Isso explica por que eles 
só ficam de conversa fiada.