When the Pengelly family first meet Lob the dog at the beginning of the story, Aiken uses a simile to describe how quickly Lob ran after a stick. Aiken writes that Lob was "like a sand-colored bullet." This simile emphasizes the speed, energy, playfulness and youth of the dog.
When Lob and his owner leave Cornwall, Sandy Pengelly, the five-year-old daughter of the Pengelly family, watches the train they are on depart from the station. Sandy has become very attached to Lob and is sad to see him go. She thinks that she will never see Lob again. When the train leaves the station, Aiken writes that it made "a melancholy wail that sounded like Lob's last good-bye." In this quotation there is an example of personification as the train is being described as "wail[ing]." This personification suggests that Sandy is so sad to see Lob leave that even the sound of the train sounds sad to her.
After Lob runs away several times from his owner, and to the Pengelly family, Lob's owner telephones the family to tell them that they may keep the dog. When Sandy hears the news she cries with happiness. Aiken uses a metaphor when she describes Sandy's father looking at "his daughter’s swimming eyes." Sandy's eyes are of course not literally "swimming," but the metaphor emphasizes how much she is crying and thus how happy she feels.
Later in the story, just before events take a turn for the worse, Aiken uses pathetic fallacy, which is when the weather is used to reflect or foreshadow the mood of the story. Aiken uses pathetic fallacy in the form of a storm. For example, she writes that the "wind was howling through the shrouds of boats." This storm creates a dark, ominous mood and foreshadows the accident in the story, when Sandy is hit by a speeding truck.