Q: "A man dressed in jeans and a black jacket is sitting down while smoking a cigarette and checking his mobile device." Does this mean that "a man smokes his first cigarette"?
A: it is not possible to tell

Q: "A young boy is sitting in a blue chair." Does this mean that "The boy is sitting in a chair."?
A: yes

Q: "A young girl is pouting her lips and holding a long-handled tool." Does this mean that "A young girl pouting and holding a tool."?
A: yes

Q: "A group of people riding on a crowded bus." Does this mean that "The bus was full."?
A:
it is not possible to tell