This refers to putting up photos of one’s children in the house, so that parents can encourage their children as they grow into adults.
It is said Japanese children are not as self-confident as children from other developed countries.
By having their photos admired, children feel that they are loved.
(so that parents can) encourage (their children as they) grow into adults
(this) refers to
nihonn no kodomo ha
jiko’koutei ga nai
self-confident are not
iwarete i masu.
(it) is said
having (photos) admired
(they) are loved