When the cherry blossom is placed in a Japanese tea cup and hot water is poured over it, the salt melts, whereupon the petals open up and float on the surface of the water.
湯のみ茶碗に入れて湯を差すことで塩漬けの塩が溶けだし、花びらが開いて湯の上面に浮いてくる。