How does Katherine Mansfield use imagery in Bliss?

Imagery:

"Although Bertha Young was thirty she still had moments like this when she wanted to run instead of walk, to take dancing steps on and off the pavement, to bowl a hoop, to throw something up in the air and catch it again, or to stand still and laugh at—nothing—at nothing, simply. What can you do if you are thirty and, turning the corner of your own street, you are overcome, suddenly, by a feeling of bliss—absolute bliss!—as though you'd suddenly swallowed a bright piece of that late afternoon sun and it burned in your bosom, sending out a little shower of sparks into every particle, into every finger and toe."

"But in her bosom there was still that bright glowing place that shower of little sparks coming from it. It was almost unbearable. She hardly dared to breathe for fear of fanning it higher, and yet she breathed deeply, deeply. She hardly dared to look into the cold mirror—but she did look, and it gave her back a woman, radiant, with smiling, trembling lips, with big, dark eyes and an air of listening, waiting for something. . . divine to happen. . . that she knew must happen . . . infallibly."