The embassy is an official state function, since the Third Reich outlived Hitler by six weeks, it would be more odd if they did not raise the flag when the head of state died. Actually Hitler’s death wasn’t officially announced until May 1st, but The Oberkommando der Wehrmacht (German High Command) obviously got the news well before that and might have informed embassies so they could bring the news out worldwide on May 1st, but perhaps the flag got lowered to half mast prematurely in Sweden.
Hitler did not invade Sweden because Sweden was traditionally a neutral country for over 200 years and Hitler did not want to bother Sweden when he already had Norway, a more strategically located nation. During the invasion of Scandinavia, Sweden kept neutral, but because much of their income was generated by exporting iron, they continued to sell it to Nazi Germany. Sweden would not help Finland fight off the Soviet attack, but 8,000 Swedes volunteered for the Finnish army. Sensing the impending trouble, nearly everyone in the country pitched in to bolster the Swedish defense lines. The meager Swedish army nearly doubled overnight from volunteers and by war’s end tripled from that. Civilians built shelters, scanned the skies for enemy aircraft, donated time and money and made military vehicles and supplies. Germany told Sweden to stay neutral, but “pro-German,” meaning they would have to abide by Germany’s demands. The Swedes would not listen to Germany’s threats and told them if Sweden was invaded they would blow up the iron ore mines. Although Sweden was surrounded by chaotic war, its citizens led relatively normal lives. However, every Swedish family was affected by it because so many civilians were called into the military reserves.
At the same time in Ireland De Valera visited the German Embassy in Dublin to sign a book of condolences for the departed Fuhrer. It was widely known what atrocities had been going on under Nazi rule by the spring of 1945. De Valera’s condolence was completely inappropriate. The Irish were certainly not allies of Nazi Germany but the people were quite conflicted whether they hated the British enough to actually support the Nazis. The British on the other hand had occupation plans for Ireland in the event that it be used to outflank the British from the Atlantic. So obviously there was little trust from the British on the neutrality of the De Valera government.
The apparatus attached to some of the vehicles (in the photos) are wood gas devices. A wood gas generator is a gasification unit which converts timber or charcoal into wood gas, a syngas consisting of atmospheric nitrogen, carbon monoxide, hydrogen, traces of methane, and other gases, which – after cooling and filtering – can then be used to power an internal combustion engine or for other purposes. Historically wood gas generators were often mounted on vehicles, but present studies and developments concentrate mostly on stationary plants.