Sexually explicit, now a buzzword intended to elicit shock and horror in the reader or listener, in the past meant "something describing or representing explicit sexual activity," i.e., actual sexual activity, such as the penetration of the vagina, anus, or mouth by a penis. Currently this buzzword is used by antisexuals and sexophobes to describe anything which includes any nudity or partial nudity, even though no real sexual activity may actually be taking place. A photo which includes the exposed breast of a girl or woman, or a photo showing the buttocks of any person, is now (incorrectly) referred to as a "sexually explicit photo". Photos which are "sexted" by young people which include any kind of nudity or partial nudity are now described as being "sexually explicit photos" even though no genuine sexual activity is taking place in the photos at all!
Sexually explicit means that something is explicit sexually.
Pedophiles and pedophile apologists claim that this is now a buzzword intended to elicit shock and horror in the reader or listener. This is because pedophiles and pedophile apologists are in denial about their sexually deviant thoughts and behaviors--behaviors which have been proven beyond any reasonable doubt to permanently damage and destroy the lives of countless innocent little boys and girls.
Sexual activity is activity that involves sex. Pedophiles enjoy sexual pleasure through activities which others may not, so--for pedophiles--these otherwise innocent activities become sexual activities, and therefore are sexually explicit activities, for which they should be removed from society by being incarcerated for life in prison or in psychiatric hospitals.