Gardening humour. Plants for sale in garden centres have images on their labels that show the plants at their best
Sometimes the plant labels show the plant as more beautiful than the plant will ever be (at least in most gardens).
A cartoon about selling flowering plants, blossoms and blooms by showing the flowers on the plant name labels.
Sometimes the flowers or plants on the labels look so much better than the actual specimen that they are almost against the trades description act.