The drawings are not correct, which makes this very confusing. To make this correct, change the collector of Q2 to a –12 volt supply. this means the transistors conduct on alternate half cycles, and the voltage on the load varies from + voltage to – voltage.
As the drawing are, the voltage on the load would vary from some positive voltage to some other positive voltage near ground, not + and – as shown. And, the input would have to swing between, for example, +10v and +2 volts, ie, never go negative.