These British collector stamps from 1915 depict four events, which are intended to remind the viewer of German crimes. They contain the following depictions: "The Zeppelin Triumph – But mother had done nothing wrong, had she, Daddy?" (top left); the execution of the English nurse Edith Cavell who provided assistance to flee ("Remember Edith Cavell, murdered October 12th, 1915") (top right); massacre of the Belgian civilian population ("Kultur – has passed here") (bottom left); the torpedoing of the passenger ship Lusitania by a German submarine on 7 May 1915 ("Remember Lusitania, torpedoed 7th May, 1915") (bottom right).
Anti-German propaganda labels, collector stamps, 1915, author: Winox; image: Wikimedia Commons https://commons.wikimedia.org/wiki/File:1915_Anti-German_propaganda_labels_by_Winox._Sinking_of_Lusitania_etc.jpg, public domain.