Ideally a plug will appear brand spanking new after a plug chop..
Insulator is white and smooth and clean (NOT grey, not microscopically pitted and no signs of tiny aluminum speckles which indicates transfer of metal from the piston or head to the plug.)
Electrodes edges are sharp under magnification (not rounded over which is a sign of melting)
And there are lot of other indicators.. But it's obvious that your plug is not getting hot enough to burn off all oil and fuel residue. If this happened, as you say, on a single run on a brand new plug, I'd suggest the mix is rich or the plug is too cold or, for some reason combustion temps are very low.
But i still have a hard time believing this plug chop was done properly.. it looks so bad that i'm thinking you allowed the engine to idle or the engine wasn't first allowed to reach normal operating temperature..