A young girl in a yellow shirt holds a large snail.
The girl is showing off her pet.
A girl might be holding a snail that isn't her pet.  And she might be holding a snail to examine it, rather than showing it off.
exists e1 s1 s2 s3 x1 x2 x3.(Theme(e1,x3) & Actor(e1,x1) & v_hold(e1) & n_snail(x3) & a_large(s3) & Theme(s3,x3) & in(x1,x2) & n_shirt(x2) & a_yellow(s2) & Theme(s2,x2) & n_girl(x1) & a_young(s1) & Theme(s1,x1))
exists e1 s1 x1 x2.(n_pet(x2) & of(x2,x1) & n_female(x1) & n_girl(x1) & a_off(s1) & Manner(e1,s1) & Theme(e1,x2) & Actor(e1,x1) & v_show(e1))