An image of a in-game peony flower appears after i broke the bottom half of a double tall grass in the savanna biome

An image of an in-game peony flower appeared after breaking the bottom half of double tall grass in a savanna.

I expected the double tall grass to disappear

An image of a in-game peony appeared

Steps to Reproduce:
1. (im not sure if it's only in the savanna biome) Go into a savanna biome.
2. Break the bottom half of the double tall grass.
3. A peony image will appear after the first two steps are completed.