That is NOT the valve cover, it is an engine cover and it does NOT have a gasket. My guess, you just had the oil changed and the oil change technician, aka grease monkey, spilled a little oil around the oil fill cap. some oil stuck to the bottom of the cover and followed along the edge and is dripping off. It will stop soon.
But, look at the front of the engine behind the bottom pulley, aka harmonic balancer, aka crankshaft pulley and look outward from there to see if there is any more fresh oil. The front seal could be leaking a little oil onto the harmonic balance where it gets slung outward, some of it hitting the bottom of the engine cover where it migrates down to the edges.