This page of the guide to Final Fantasy 7 Remake has a description of another Discovery - The Language of Flowers. You can unlock it in Chapter 8 - Budding Bodyguard.
To see this scene, you must complete all side missions in the sector: The Mysterious Moogle Merchant, Kids on Patrol, Weapons on a Rampage, A Verified Hero, The Angel of the Slums, Paying Respects. On the way home, Aerith will ask you to go with her to the meadow to see her flowers.
Follow Aerith and you will have a conversation with her. She will tell you about her bond with flowers and nature. It is a purely story-related sequence which deepens the relations between Aerith and Cloud.
Reward: None, although you can pick up MP UP Materia near the meadow. Useful for casters, including, of course, Aerith.