  Herbig-Haro flows discovered in photoionized medium forms a separate category
and detailed studies of which become one of the key issues to our understanding
of jet production and evolution. The Rosette HH2 jet is the second of such
flows that immersed in the spectacular HII region of the Rosette Nebula.
However, its disconnected jet components are detached from the proposed energy
source, have additional unusual properties and thus a disputable nature. In
this paper, we investigate through high-quality echelle spectrographs the
physical nature of the jet system. The jet shows distinctly different velocity
components. It is believed to be composed of a fast neutral jet with an
approaching velocity of -39.5 km $^{-1}$ as respect to the systemic rest frame,
and likely an extensive, photoevaporated envelope dissolving at roughly the
sound speed. This led us to infer a fast dissipating nature of the jet system
being bathed in the fully photoionized medium of Rosette.
  In addition, time series photometric observations provide evidence that the
energy source is highly variable, with amplitudes of up to ${>}$ 1 mag in R &
I. This is consistent well with an early evolutionary status of the jet driving
star with a red, late type spectrum in the optical.
