Braille requires the following things: multiple grids of 3×2 and a series of black dots. There is but one such grid on the card, and it is on the front. Have you noticed that flowers like the Yellow Pond Lily or Bitter Dock sometimes have a dark leaf, that is not present on the other flowers of the same kind?
Solution of this Step
You should see the flower grid on the front as a 4-letter braille grid (four grids of 3×2). Flowers with a dark leaf are a version of the black dot. If you work your way through the flowers in this manner, you should find the braille symbols for the letters T, R, E and S.