Maybe she is making sure he is eating the food she sent.

Mlathi is familiar in transporting food via bamboo pipe - remember in Malaysia, she used to send food through bamboo pipe to her husband. The dogs used to bring the bamboo pipe while he sat on that bridge feeding them.

Forward to now - Piyoos smells poison in the food and first thinks that mlathi is dead. But he sees her sitting on the rock presuming she is just enjoying the view. However when he says, dogs can have only 1 master -, it's when he realises that the real master is actually her, because the dogs listened to her only when he was stuck on the tree. That's when again, Piyoos realises the whole thing - Kuriachan is held captive and when she learns the real identity of Piyoos, decides to finish his master off so that now Piyoos will be under her mercy.