Bradbury makes frequent use of personification, attributing personal or human-like traits to a number of inanimate objects in the story.
In some cases, Bradbury describes inanimate objects as if they possess body parts, and he characterizes their physical actions and reactions in human terms. We can see this when the house is burning:
"The house shuddered, oak bone on bone, its bared skeleton cringing from the heat, its wire, its nerves revealed as if a surgeon had torn the skin off to let the red veins and capillaries quiver in the scalded air."
In other cases, Bradbury attributes mental and emotional states to objects, as in this description:
"…it had shut up its windows and drawn shades in an old-maidenly preoccupation with self-protection which bordered on a mechanical paranoia."
How does personification affect the story?
A good way to approach this question is to ask how different the story would feel if Bradbury had portrayed his inanimate objects without making any reference to human traits.
Clearly, personification invites us to feel a certain empathy for these objects. It's one reason why this story evokes an emotional response in the reader.
But these elements of personification do more than lend immediate emotional color to an action. Psychologists argue that when we attribute human characteristics to an object, we are encouraging the mind to tap into our broader understanding of how human beings think, feel, and behave.
If the house is merely an automated house, then its behavior is simply a series of mechanical operations, and the story is just a tale of a machine left running because nobody turned it off. But if we think of the house as a person, then it has a psychology, and its behavior can be perceived in many other ways -- as confused, irrational, or uncomprehending in the wake of abandonment. It keeps making meals that nobody eats; it reads poems that nobody hears. What kinds of human situations does this evoke? How do the events of the story relate to things we have experienced or witnessed?
So Bradbury's use of personification doesn't just make us respond to the immediate meaning of his metaphors ("the fire was clever"). It also leads us to go beyond the words he uses, and associate his objects with a wider range of thoughts, motives, and feelings.