To begin, one must first understand what imagery is. Imagery is
the forming of mental images, figures, or likenesses of things. It is also the use of language to represent actions, persons, objects, and ideas descriptively. This means encompassing the senses also, rather than just forming a mental picture.
Therefore, imagery appeals to all of a person's senses: taste, touch, sight, sound, and taste. The way an author writes will either allow a reader to create mental pictures of what is being described, as well as, feeling them according to any/all of the senses which are "targeted."
In The Borrowers, imagery can be found in the opening paragraph:
How could it have been me- a wild, untidy, self-willed little girl who stared with angry eyes and was said to crunch her teeth.
In this line, an engaged reader can certainly form a mental image of the little girl being described. While this image may differ for each reader, one can must assuredly picture a small girl with unkempt hair and large eyes. Not only does this description provide a mental picture, it evokes the senses of the reader.
The reader can "see" teeth being ground together, "hear" the sound which accompanies the grinding, and "feel" the grinding based upon their own experiences with the movement.
In the following paragraph of the opening chapter, Norton describes the "breakfast room." This detailed description of the room, again, provides the reader with a distinct picture of the area along with images which appeal to the senses.
When the sun streams in on the toast and marmalade, but by afternoon they seem to vanish a little and fill with a strange silvery light.
Here, the imagery appeals to the senses of taste, touch, and sight. The reader can "feel" the sunlight on their skin, "taste" the toast and marmalade, and "see" the sun streaming into the room. Later, the reader can "feel" the difference of the room as the sun's rays leave. A new coldness is described and the reader's initial feeling of warmth is replaced by cold.