When breaking Tall Grass in a Plains biome it will flash as a Sunflower

When looking at the top of the tall grass it says this in F3

Block: minecraft:double_plant/8
Model: flower_sunflower_bottom
Facing: South
Half: upper
variant: grass

When looking at the bottom

Block: minecraft:double_plant/2
Model: flower_grass_bottom
Facing: South
Half: lower
variant: grass