What are the two speakers talking about?

W: Hey you! Can’t you be a bit faster? You make the whole group wait for you.
M: How can you blame it on me? I’ m having trouble in operating this kind of machine. It is designed for you righthanders.
W: You always complain about these machines. But have you ever tried to find reasons in yourself? You are not the only one using your left hand after all.
M: Really? I don’t know any others who are the same as me.
W: To tell you the truth, I’m also left-handed.
M: You?
W: Yeah. You should spend some time getting used to the machine in advance. Then you can do it quickly.
M: Is that what you have done?
W: Yes. In fact, it pays to use both hands.
M: OK, I will try.