You won’t smell anything if the spark plug tubes are ingesting a bit of oil from the cover. You would see some oil in the tubes. Takes a flashlight and a few seconds with the plugs out.
After looking at it again (with a little more sleep) its probably not that. I can’t see any oil around the other parts except the threads. Probably just gunk that previous plugs pulled into the thread and got on there when the next plugs went in. No big deal.