Should Fat Man and Little Boy fall on the Reich, I think you could have a slightly different view of them post war. One of the images that (IMHO), has stuck in the mind and collective conscience is the view of Hiroshima showing a flat townscape, making it look potentially more destructive than it was. Against a brick and stone built town, the devistation may not look as bad.
Potentially, post war, this could lead to an underestimation of the effects and increase the possibility of WWIII.
that depends were the Atomic bomb is drop, Germany was full with towns with half-timbered houses. no match for 10 Kt atomic bomb air burst.
like the town of Weimar, Heidelberg, Munich or Frankfurt am Main, or what was left over after USAAF and Bomber Harris run riot.
after the detonation will only standing concrete air-raids bunkers.
The Impact of NOT dropping the Atomic Bomb on Japan will have fast consequence on it's Culture and Anime & Mangas!
no Godzilla, no Japanese superheroes like Son Goku, who destroy entire planets during hand to hand combats.
While In Germany will have very traumatic experience of use of Atomic Bomb on them.
With drastic impact on there Culture, Film, Novels and later on Comic and TV.
There will be allot of Novel, Movies, Theater-plays about the Role of National Socialism and it deathly atomic consequence.
like adaptation of
Goethe's Faust were Faust get deal with Devil
and become a National Socialist and become irrevocably corrupted in end he die in Atomic explosion as modern version of Hell
also the argument "For crimes we commit against humanity, We deserved the Atomic bomb as punishment" will be common in Germany.
on Political level the Germans try to abolish the Atomic, Biological and Chemical weapon worldwide.