It's def. not mold, that much I am sure. It's too fine of a coat to be mold and mold grows in patches, not evenly all over the cigar. If every other cigar in the humi looks the same, then it's from using non-distilled water in the humidifier. It is hard to tell because of the pictures, but it looks like you might have yourself some fine aged sticks there!
Just thought of something....look at the shelves and other boxes to see if you can see or feel the powder on them as well. If it's mineral deposits from not using distilled water it'll be all over everything in there. If they're clean, I'd say you scored!