A crowd of standing and sitting people taking their own pictures with multiple cameras.
A group of individuals taking selfies.
Both crowd and group can be used to describe a number of people congregated together, and if they are taking their own pictures, it can be assumed that they are taking selfies.
exists e2 e1 s1 s2 s3 x1 x2 x3 x4 x5 x6.(a_topic(s1) & subset_of(x3,s1) & Theme(e2,x5) & Actor(e2,x4) & v_take(e2) & with(x5,x6) & n_camera(x6) & a_multiple(s3) & Theme(s3,x6) & n_picture(x5) & a_own(s2) & Theme(s2,x5) & of(x5,x1) & n_thing(x1) & (x3 = x4) & n_people(x3) & Actor(e1,x3) & v_sit(e1) & subset_of(x1,s1) & of(x1,x2) & n_standing(x2) & n_crowd(x1))
exists e1 x1 x2 x3 x4.(a_topic(x1) & of(x1,x2) & Theme(e1,x4) & Actor(e1,x3) & v_take(e1) & n_selfy(x4) & (x2 = x3) & n_individual(x2) & n_group(x1))