Which of these is the more appropriate theme statement for the poem "Barbie Doll"? "Sometimes, other people's expectations on outward beauty...

While both statements of theme seem appropriate, perhaps
the first one strikes more immediately at the tension created in the fifth
line:

Then in
the magic of puberty, a classmate said:

You have a great
big nose and fat legs.

These
lines are central to the controlling metaphor of the "girlchild's" not meeting the
standards set by society for beauty with a teenaged girl.  For, the girl's
self-perception changes after the classmate derogates her appearance.  Even though she
is healthy and athletic, the girl henceforth apologizes and she believes that "Everyone
saw a fat nose on thick legs."

The third stanza clearly
indicates the young woman's desire to conform as she takes advice on how to "exercise,
diet, smile and wheedle," thus losing her personal identity.  All that is important to
her is her identity by means of her conformity.  However, when she cannot conform to the
idea of beauty set forth by the classmante, the young woman despairs and dies.  But, in
the casket with her putty nose, she at last conforms:  "Consummation at last."  [As you
say, she loses her personal identity and unique nature.]  The authors rage, of course,
is evident in this ironic line.

The first statement of
theme, thus, follows the arrangement of the poem and is validated by this
arrangement.