In the poem "Same Song" by Pat Mora, what theme, or message, do you think the poem conveys? Is that message true only for young people?...

This poem applies to adults as well as children. It is
about superficial beauty. Depending on the society, certain physical features are
accepted (endorsed and ‘passively’ accepted) as beautiful. Typically, these are things
like symmetry and athletic or curvaceous (females) body types. And although beauty is
subjective, there are clearly certain types of beauty that dominate because media,
artists and advertisers endorse iconic images that many passively accept as “essential”
or the best idea of beauty.

The “same song” means that both
of his children have been affected by this anxiety of living up to society’s “majority
rule” of physical beauty. It is also a "same song," because this is a recurring
historical situation. Both children “frown” despite their best efforts. The images of
beauty that bombard us (via media, art, internet, etc.) are impossible to live up to.
This is certainly true in the age of air brushing and Photo Shop, but it has always been
the case, especially with external beauty, that people go to great lengths to live up to
these impossible standards. The pursuit of external beauty is bound to affect the child
or the adult psychologically unless he/she can accept the superficiality of it
all.