What does the image of Divine Mercy mean?

In 1931, Our Lord asked St. Faustina to have an image painted of His Divine Mercy along with the words, “Jesus, I trust in You.” He said, “I desire that this image be venerated, first in your chapel, and [then] throughout the world.” (Diary, 47)

Jesus further added,

“I promise that the soul that will venerate this image will not perish. I also promise victory over (its) enemies already here on earth, especially at the hour of death. I Myself will defend it as My own glory.” (Diary, 48)