Cat: Concatenates the given sequence of seq tensors in the specified dimension. The consequence is usually that a certain dimension changes dimensions e.g. dim=0 You then are incorporating elements to your row which enhances the dimensionality on the column Room. But I am undecided if "untypical" is the correct phrase. https://www.theorthopaedicandpainpractice.com/lower-back-pain-treatment-stretches-a-simple-effective-guide-to-relief-and-recovery/