premise: A group of smiling people are posing outdoors for a picture.
hypothesis: The group of people are smiling for their family photo.
explanation_1: You can not infer it's for a family photo.
explanation_2: Every picture is not a family photo.
explanation_3: There is no indication they are a family.  They could just be friends, or even strangers.
premise_logic: exists e2 e1 x1 x2 x3 x4 x5.(for(e2,x5) & n_picture(x5) & Theme(e2,x4) & Actor(e2,x1) & v_pose(e2) & n_outdoors(x4) & Theme(e1,x3) & Actor(e1,x2) & v_smile(e1) & n_people(x3) & (x1 = x2) & n_group(x1))
hypothesis_logic: exists e1 x1 x2 x3 x4.(n_photo(x3) & of(x3,x4) & n_family(x4) & of(x3,x1) & n_thing(x1) & n_group(x1) & for(e1,x3) & Actor(e1,x1) & v_smile(e1) & of(x1,x2) & n_people(x2))