well I want to use these tensors to index into a rank 4 tensors of batches of images and color them in according to them being an example of true positive etc, i.e. I write this for an image tensor of shape 4xCxHxW
images[tp,:] = ...   # manipulating the color channels
images[tn,:] = ...
...

and I was convinced that it works by visual inspection. However, know I am not sure anymore. By looking at your example above about the nature of indexing, I suspect that indexing into images does not yield what I want, namely the specific image at the position at which the indexing tensor features ones. Or does it?
For index tensors containing only zeros and ones that would mean, that I would only ever access the first and second image in the batch. However, my test runs showed colors for the entire batch. But then, wouldnt this  indexing behaviour contradict the by you before mentioned way how indexing works?