What does it mean to hide spring scenery in the little boy's sleeve?

This is a pair of couplets. The first sentence is: flowers are hidden in the sleeves, and young people hide spring scenery.

The bottom line is that the mirror is hung in front of the hall, and the eyes of adults are sharp.

The story is that the father took his son to a friend's house for dinner. My son was fascinated by the blooming peach blossom, so he secretly broke a branch and put it in his sleeve. As a result, his father and others saw it. My father directly reprimanded many friends for their bad faces, so he wrote the first couplet "Flowers in the Sleeves Hide Spring", and his son gave the second couplet "Hanging a mirror in front of the hall, adults with sharp eyes", and the result was full of applause. His father was so proud that he forgot about his son's folding flowers.