  Solar jets are collimated plasma flows moving along magnetic field lines and
accelerated at low altitude following magnetic reconnection. Several of them
originate from anemone-shaped low-lying arcades and the most impulsive ones
tend to be relatively wider and display untwisting motions. We aim to establish
typical behaviours and observational signatures in the low atmosphere that can
occur in response to the coronal development of such impulsive jets. We
analysed an observed solar jet associated with a circular flare ribbon, using
high-resolution observations from SST coordinated with IRIS and SDO. We related
specifically identified features with those developing in a generic 3D
line-tied numerical simulation of reconnection driven jets, performed with the
ARMS code. We identified three features in the SST observations: the formation
of a hook along the circular ribbon, the gradual widening of the jet through
the apparent displacement of its kinked edge towards, and not away from the
presumed reconnection site, and the falling back of some of the jet plasma
towards a footpoint offset from that of the jet itself. The 3D numerical
simulation naturally accounts for these features which were not imposed a
priori. Our analyses allow to interpret them in the context of the 3D geometry
of the asymmetric swirled anemone loops and their sequences of reconnection
with ambient coronal loops. Given the relatively-simple conditions in which the
observed jet occurred, together with the generic nature of the simulation that
comprised minimum assumptions, we predict that the specific features that we
identified and interpreted are probably typical of every impulsive jet
