This picture here would have been taken from a German defence at Juno Beach. Because of the ships you can see off shore it would have been taken sometime after the beaches had been taken. There would be many defences like this one along the beaches to help defend them. The gun inside the bunker is a German anti-tank gun which would be able to penetrate tanks armour and destroy them. It would also have the ability to fire HE rounds to kill soldiers or destroy landing craft. The Hedgehogs in the water would be to stop tanks from coming onshore by having them get stuck on them and unable to continue an advance towards German defences. They might have also been used alongside mines to destroy allied landing craft or to stop them from advancing. If they weren’t in the water soldiers could have used them for some cover from enemy fire. Right below the barrel of the gun you can see what appears to be a landing craft, this would have been used to bring soldiers onto the beach, but it looks like it got destroyed while bringing soldiers. Outside the bunker window you can see the damage the defences took during the invasion. This could have been caused during the landings from soldiers and tanks or from Allied fire before the landings from ships/planes. The ships you can see could have helped attack German defences before the landings to help destroy some of them and would have carried the landing craft, tanks, soldiers, and supplies.
Germans prepare defences on the beach
The Canadian 3rd division reserve troops coming ashore at Bernieres at the Nan sector of Juno beach