narrator provides a lovely description of the moonlight that spills out and lights the scene as Mary and Warren sit together on the porch discussing Silas.

A metaphor is a comparison that does not use the words "like" or "as," while a simile is a comparison that does use the words "like" or "as." Frost writes a simile when he calls the morning glory "strings" "harp-like." Morning glories are normally trained to climb up the posts of porches or up trellises. The vines that climb straight up can look like strings, especially when the morning glory flowers are closed up for the night. In the moonlight, the morning glory vines look to Mary like the strings on a harp as she reaches out and touches them.

This leads to a second simile, in which Mary's hand, placed gently on the morning glory vines, is likened to Mary playing a tender tune that touches Warren's heart. Mary then tells Warren that Silas has come "home" to die.

This section of "The Death of a Hired Man" talks about the moon, and is full of beautiful, literary descriptions of the moon. He begins by saying "Part of the moon" which is a synechdoche. It means referring to part of an object when you are really talking about the entire thing. For examples, someone might be "counting heads". Although they are counting heads, we know that really they mean the entire person.

In the same way, the moon is not actually breaking into pieces, but rather the moon is moving across the sky and only a part of it is visible and being described in this line.

"Dragging the whole sky with it" is of course a hyperbole as well, since the sky is not falling toward the west. He is using this line to create an image, perhaps one that focuses on the changing of light and the way all the lights in the sky seem to follow the moon, so that the darkness of the sky makes it seem like there is nothing there.

"It's light poured in her lap" could be a form of personification, since the moon itself can't actually pour anything. It is also a metaphor for the way in which light is cast upon her.

Finally, this poem, especially this section, is filled with imagery. There are tons of vivid description which make the reader able to see and smell the images of the poem. These include descriptions like "harp-like morning glory strings" and "dew from garden bed".

The imagery in this section of Frost's poem pertains to the moon, which is said to be "falling down" the sky. This is metaphorical—obviously, the moon is not really falling, but this is how it appears. The moon is personified and given human attributes and agency; it is "dragging" the rest of the sky along with it.

We also see a metaphor in the representation of moonlight, which "poured softly in her lap." The lighting pouring softly is representative of the way the light from the moon is cast on her.

The strands of moonlight are described as "harp-like," which leads on to another piece of vivid imagery: the woman, into whose lap the moonlight has so beautifully poured, reaches out to touch these strings of moonlight, "as if she played" them, eking out tender sounds with the moonlight as her instrument. This is a metaphor—the woman is not really playing music out of moonlight, but the way she reaches out to touch the strands of light suggests this to the speaker.

In line 103 of "The Death of the Hired Man," there is a metaphor in which the moon is compared to a force that can drag down the entire sky to the west, creating the dawn. In line 107, the rays of light coming in through the window are compared, in a metaphor, to the strings of a harp. In line 109, there is a simile in which the woman is compared to someone who plays on the harp the tenderness that affects her husband. In a later metaphor (in lines 116-117, beyond the point you asked about), the dying hired man, Silas is compared to the dog that came out of the trail in the woods, tired from his wanderings, to Mary and Warren's house. Warren says that Silas means as much to them as that dog does. Of course, Silas does mean more to Mary and Warren than the dog, and that is why he comes to their house to die in the end.