The photometric variability of cosmic objects causes light echoes in the ambient medium. Searching the VVV/X survey for scattered light changes from massive young stellar objects (MYSOs) revealed an echo from G339.88-01.26 - but in an hitherto unseen fashion. It points to an illumination behaviour temporally alternating between the two the bipolar cavities with a period of about seven years. This time scale indicates a modulation which originates close to the MYSO, perhaps due a tilted precessing inner disk. Our mid-infrared VLT images clearly show the bipolar morphology of the MYSO. Remarkably, the scattering cavities are aligned with the chain of methanol and water masers. The eastern one is brighter, thus facing towards the observer, which is consistent with the radial velocity gradient of the masers. The MYSO is behind or buried in a dense filament which runs non-orthogonal with respect to the orientation of the cavities. While these findings contribute to a more consistent picture of G339.88-01.26, the periodic asymmetric brightness changes still lack an explanation.