In short, tensor is a invariant something and
In Computer Engineering, for the convenience of calculation we modify a vector to multi-dimension array like $$[1,2,3,4] \rightarrow [\begin{matrix} 1 & 2 \\ 3 & 4 \end{matrix} ]$$
But dose we said that the above change keep invariant? or just isomorphic mapping?
Because I understand invariant of tensor only applies when it's the same mathematical structure. like bellow $$[1,2,3,4] \rightarrow [2,4,5,6]$$