I know I'm nine months late but I think I understand your confusion. This event has nothing to do with tattoos in the sense of markings on the skin, which is what I assume you disagree with the state endorsing. A tattoo in this context is the British English usage: "an entertainment consisting of music, marching, and the performance of displays and exercises by military personnel." This footage is taken from the Sweden International Tattoo, an event at which many other military bands and display teams from across the world also performed. Famous examples of tattoos include the Royal Edinburgh Military Tattoo and the Basel Tattoo in Switzerland. To go into more detail, if you were interested enough which I doubt, according to Wikipedia: "The term '"tattoo" derives from a 17th-century Dutch phrase doe den tap toe ("turn off the tap") a signal to tavern owners each night, played by a regiment's Corps of Drums, to turn off the taps of their ale kegs so that the soldiers would retire to their billeted lodgings at a reasonable hour.[1] With the establishment of modern barracks and full military bands later in the 18th century, the term "tattoo" was used to describe the last duty call of the day, as well as a ceremonial form of evening entertainment performed by military musicians." This is separate from the origin of the more common word "tattoo", which is actually an anglicised version of the Samoan word "tatau".
