Brushstroke by Roy Lichtenstein in the Museo Nacional Centro de Arte Reina Sofía, Madrid, Spain.

http://www.museoreinasofia.es/en/collection/artwork/brushstroke

https://en.wikipedia.org/wiki/Roy_Lichtenstein

https://en.wikipedia.org/wiki/Museo_Nacional_Centro_de_Arte_Reina_Sof%C3%ADa