No, a personification is when you give an inanimate object human qualities.
Yes, "the sky is low" is an example of personification, as it gives human characteristics (being low) to the sky.
The dark sky was angry and resentful.
metaphor
The sky roared with anger!
Yes, "under the jewelled sky" is an example of personification because the sky, an inanimate object, is described as having the qualities of a jewel, which is typically associated with beauty and value. This personification adds an element of vivid imagery and enhances the poetic quality of the description.
In "The Sky is Low," Emily Dickinson personifies nature by describing the sky as bending down to touch the earth. This personification gives the impression that the sky is actively participating in the scene.
Uranus (Ouranos meaning "sky" or "heaven") was the personification and god of the heavens/sky.
Caelus, the personification of the sky.
personification
In the darkness the moon smiled in the sacred sky
Sunlight smiles in the sky (also alliteration :])
Sky Low Low is 3' 6".
Métaphore