  We present bispectrum speckle interferometry of the massive protostellar
object IRAS 23151+5912 in the near-infrared K' band. The reconstructed image
shows the diffuse nebulosity north-east of two point-like sources in
unprecedented detail. The comparison of our near-infrared image with mm
continuum and CO molecular line maps shows that the brighter of the two point
sources lies near the center of the mm peak, indicating that it is a high-mass
protostar. The nebulosity coincides with the blue-shifted molecular outflow
component. The most prominent feature in the nebulosity is a bow-shock-like
arc. We assume that this feature is associated with a precessing jet which has
created an inward-pointed cone in the swept-up material. We present numerical
jet simulations that reproduce this and several other features observed in our
speckle image of the nebulosity. Our data also reveal a linear structure
connecting the central point source to the extended diffuse nebulosity. This
feature may represent the innermost part of a jet that drives the strong
molecular outflow (PA ~80 degr) from IRAS 23151+5912. With the aid of radiative
transfer calculations, we demonstrate that, in general, the observed inner
structures of the circumstellar material surrounding high-mass stars are
strongly influenced by the orientation and symmetry of the bipolar cavity.
