What are the similarities and differences between the two metaphors in Ode to Snow?

What does snow look like? "Brother Hu said," The difference between sprinkling salt and air can be simulated. Brother and daughter said, "If catkins are not caused by the wind." These two metaphors compare salt to snow and catkins to snow. The same thing is that both of them are white, and they are really scattered in the air like snowflakes. The difference is that catkins, as a kind of spring scenery, just like flowers, rise from the wind, drift without roots and fly all over the sky. Compared with the north wind, which is full of snow, it is perfect. Catkin is bigger than its words, pointing out the scene of "sudden heavy snow" at that time, and "because of the wind" pointing out its natural characteristics of dancing with the wind and rambling. Look at the metaphor of "sprinkling salt in the air" again, and it will be embarrassing. Metaphor is more spiritual: salt is scattered in the air, falling heavily, and it is too late to hide. What about appreciation? No sense of beauty.