Final answer:
The contrast assumption suggests Lydia would identify the unknown object as the turtle, contrasting it with her known pet dog when instructed to 'Look at the turtle!' by her father.
Step-by-step explanation:
According to the contrast assumption in psychology, when Lydia's father says, "Look at the turtle!" and Lydia is presented with two objects - her pet dog and an unknown object - Lydia would assume the unknown object is the turtle.
The contrast assumption is a cognitive principle suggesting that individuals use context and differences in options to identify unknown entities. If Lydia knows one object is her dog, and she hears a reference to a turtle, she'll contrast the known (her dog) with the unknown and deduce that the unknown object must be what her father is referring to.