My advice - do not top up just because the oil level is fluctuating between the Min/Max marks which are those two marks you see in your picture, if the warning light did not light up to ask you to top up (unless you damn suay and the sensor failed). Sometimes the level fluctuates from Max to some where between the two marks because of EO being thrown around or sloshed in the case when the car is moving.
Last time I had a gasket leak that had to be repaired by a dealer's workshop more than three times. To cut the long story short, those f***king useless buggers were simply... useless - failed to repair the leak and each time they topped up 1-2litres of oil thinking the oil had leaked away (they said indicator was showing min mark too).
After so many failed attempts, I turned to Doc who saved my arse. While repairing the faults, he found TEN (10) liters of oil in the engine. Luckily the engine was not damaged and worked fine (this also proved that BMW engines are damn strong, cos if it were my Hondas surely the engine would have chiu'ed).
