Q: "A concert in which the two people on stage both hold guitars." Does this mean that "People are playing a rock song."?
A: it is not possible to tell

Q: "A shirtless man uses a long reaching tool to paint a ceiling white." Does this mean that "The man calls a contractor to paint his ceiling."?
A: no

Q: "Several people standing in a group talking on phones and looking upward." Does this mean that "They are looking for something."?
A: it is not possible to tell

Q: "A man is sitting down and playing a guitar like instrument." Does this mean that "A man playing a stringed instrument."?
A:
yes