Q: "A group of people is gathered outside a building listening to a man on the stairs speak." Does this mean that "There's a group of people listening to a male speaker."?
A: yes

Q: "A little boy is losing a game of strip checkers." Does this mean that "The little boy is sad."?
A: it is not possible to tell

Q: "Two couples are dancing in an open-air retail area." Does this mean that "Couples are doing a dance performance."?
A: it is not possible to tell

Q: "two guys one in red and the other in black sitting at computers" Does this mean that "some guys are sitting at computer"?
A:
it is not possible to tell