Final answer:
Janie's grandmother dreamed of a better life for her granddaughter. The irony lies in Janie's vision of stability contrasting with her grandmother's desire for her to aim higher.
Step-by-step explanation:
Janie's grandmother had a dream for her granddaughter to have a better life, symbolized by the metaphor of picking from a higher bush and sweeter berries. This dream represents Janie's grandmother's desire for Janie to have more opportunities, experiences, and happiness.
When contrasted with Janie's vision of her life as a tree, her grandmother's words are ironic because the tree represents stability, rootedness, and contentment. Janie's grandmother's words imply that she wants Janie to seek more in life and not be content with what she already has.