What does the word cardboard denote in the poem?why has this word been used. Hornbill (photograph)

What does the word cardboard denote in the poem?why has this word been

1.	What does the word cardboard denote in the poem?why has this word been used. Hornbill (photograph)
Answer» It denote photograph cardboard denote here the photograph of three girls at beach who are poetess mother her two cousin sisters. Photograph actually was the memories of her mother and this poem gives a lesson that "nothing is immortal as nature" this lesson was given by poetess with the help of photograph .