Two men are waiting to be interviewed, while another checks the mics.
The men are preparing for a news conference.
Sentence 1 does not provide any indication that a news conference is about to take place.  Sentence 1 also does not specify that the men are preparing, just waiting.
exists e1 p1 x1 x3.(n_mic(x3) & Topic(e1,p1) & Actor(e1,x1) & v_wait(e1) & exists e2 p2.(exists e3 x2.(Theme(e3,x3) & Actor(e3,x2) & v_check(e3) & n_thing(x2)) & while(e2,p2) & Theme(e2,x1) & v_interview(e2)) & n_man(x1) & card_eq_2(x1))
exists e1 x1 x2 x3.(n_man(x1) & for(e1,x2) & n_conference(x2) & of(x2,x3) & n_news(x3) & Actor(e1,x1) & v_prepare(e1))