Looks like your oil drain-plug has been pushed-in to the bottom of the oil-pan.
It may have happened when the engine was rested on the floor, with the drain-plug taking the weight.
Anyway, the drain-plug doesn't appear to be leaking, but it is no longer the lowest point in the pan.
So that when used-oil is drained through the plug, not all of the oil will come out. Not a big problem, except that any debris in the oil might can left behind in the pan.
If you are thinking of resealing the oil-pan, then replace the oil pan with an undamaged one.