  Until now the existence of extended emission is an intriguing property of
short bursts. It is not clear what is the nature of the extended emission. It
might be a rising x-ray afterglow, or it could be a manifestation of the
prolonged activity of a central engine. We consider short duration gamma-ray
bursts, emphasizing the common properties of short bursts and short burst with
extended emission. Assuming that the extended emission with broad dynamic range
is a common property of short bursts, we propose a two jet model which can
describe both short main episode of hard spectra emission, specific for short
bursts, and softer spectra extended emission by different off axis position of
observer. The toy model involves a short duration jet powered by heating due to
$\nu\tilde{\nu}$ annihilation and long-lived Blandford-Znajek jet with
significantly narrow opening angle. Our proposed model is a plausible mechanism
for short duration burst energization, and can explain both short burst with
and without extended emission within a single class of progenitor.
