Q: "A white dog catching a treat in his mouth." Does this mean that "A dog catches a treat."?
A: yes

Q: "A girl running with a basketball, while another tries to steal the ball from her." Does this mean that "Two girls on opposite basketball teams are competing in a game."?
A: it is not possible to tell

Q: "A man wearing a hat and scarf stands in a crowd." Does this mean that "A man wearing a hat and scarf"?
A: it is not possible to tell

Q: "A group of women, dressed in safety gear, are on rollerskates and skating in front of a large group of people." Does this mean that "Women dressed in safety gear are skating."?
A:
yes