Source: Wikimedia, German Bundesarchiv

Original caption translates to: Western Front, Grenadiers advance near Aachen - Enemy incursion into the main battlefield is cleared. In a sector of the front around Aachen, the enemy has broken into the main battlefield. Grenadiers immediately move in to clear the incursion. With rifles at the ready, they advance through a forest clearing.

Photo taken by a Mr. Lohrer, first name unknown