Well, we need to discuss what sexually explicit conduct is. Not by any stretch of the imagination is a hand up a skirt ANY of these things.
http://www.law.cornell.edu/uscode/718/usc_sec_18_00002256----000-.html
(A) Except as provided in subparagraph (B), “sexually explicit conduct” means actual or simulated—
(i) sexual intercourse, including genital-genital, oral-genital, anal-genital, or oral-anal, whether between persons of the same or opposite sex;
(ii) bestiality;
(iii) masturbation;
(iv) sadistic or masochistic abuse; or
(v) lascivious exhibition of the genitals or pubic area of any person;
(B) For purposes of subsection 8(B) [1] of this section, “sexually explicit conduct” means—
(i) graphic sexual intercourse, including genital-genital, oral-genital, anal-genital, or oral-anal, whether between persons of the same or opposite sex, or lascivious simulated sexual intercourse where the genitals, breast, or pubic area of any person is exhibited;
(ii) graphic or lascivious simulated;
(I) bestiality;
(II) masturbation; or
(III) sadistic or masochistic abuse; or
(iii) graphic or simulated lascivious exhibition of the genitals or pubic area of any person;
Edit:
And just to clarify, "graphic" means
(10) “graphic”, when used with respect to a depiction of sexually explicit conduct, means that a viewer can observe any part of the genitals or pubic area of any depicted person or animal during any part of the time that the sexually explicit conduct is being depicted;
In the photo could you see any of her genitals or pubic area?