What does this plug tell about the inside operation of the engine? I can't find any plug that looks like this in any online charts.
Next time make a picture before you cleaned and sanded the plug, the color of the electrode can tell a lot about operating conditions.
To answer your question: it looks a bit fouled with oily deposits, so its possible the engine is running too rich.
What kind of bike is this plug out of? Is it carbureted or fuel injected? As far as your fuel to air ratio, you can install new plugs and do a plug chop