Two women, standing at a fence, are each talking on their cellphones, while two men sitting on the opposite side of the fence are having a conversation.
The two men and women are talking to people that they know.
there is insufficient detail to give an answer about the women and men
Women implies a group while two women gives a specific amount.
Sentence 1 states the subjects are talking on their cellphones and sentence 2 states the subjects are talking to people.