The Rosetta probe is orbitting the Comet at the moment.
Anomalies are found in the mass/volume relation of the comet ( too heavy)
Secondly it seems to expand in volume given by the linear impressions at "the head of the rubber duck".
My own interpretation of electric Comets is: that they are formed by ( new physics) micro dark matter black holes.
Comet 67P seems to be based on at least two BH nuclei.
IMHO, the smallest black hole could be interpreted as stringy quantum knot produced by electro magnetic interference at the solar surface being the start of small comets or by the so called sprites above thunderclouds. See: https://www.flickr.com/photos/93308747@N05/?details=1 and
Ball Lightning, Micro Comets, Sprite-Fireballs, Solar Bright Points and Xray/ Gamma Flashes According to Quantum FFF Theory. http://vixra.org/pdf/1104.0044v6.pdf
And : The Impossible Zero Point Electric Black Hole as the Origin of New Physics even for Comets like 67P,C-G.http://vixra.org/pdf/1402.0044v3.pdf
New physics could be found if the Comet shows also an electric and magnetic field created by both dark matter black holes expected to be the origin of a system (circuit) of Birkeland Alfven currents between them.
Also gravity anomalies should be found at both sides of the extended symmetric centerline of the rubber duck.
The huge crater at the top of the head of the duck could be a tell tale.
At the bottom of the duck there are three large craters, so this could be a sign for multiple (3?) micro BHs.
The origin of the circular craters at the surface of 67P C-G.
If we assume that all circular craters at the surface of comet 67P are originated by two aligned gravitating new physics fermion repelling micro black holes (BH), then we may get an impression of the inner BH structure of the comet responsible for the shape.