Żarówka żwiecowa płaska and other 65,000 icons from Icons8 icon pack follow the visual guidelines of the operating systems: Windows, iOS, Android KitKat, and Material. PNG format is free up to 100x100 px. Icons are availble for download in PNG and vector (SVG, PDF, EPS, and more).
The icon is a simple egg shaped bulb, jutting from a fixture. The light bulb stands vertically tall above its fixture, which tapers down to the socket where it plugs for power. The inner workings of the bulb are not depicted, nor anything that would imply the bulb being lit.