If you squint hard enough, you can see all of them as linear transformations (even the 2D images :-). I politely disagree about covariance and Hessians. I can

If you squint hard enough, you can see all of them as linear transformations (even the 2D images :-). I politely disagree about covariance and Hessians. I can squint and say that the Hessian provides a change in gradient when multiplied by a delta vector. Similarly for covariance... Or you could look at it as one half of the dot product for a Bhattacharyya distance, which is just a product of three matrices (row vector, square matrix, col vector). No need for tensors yet. That is unless you decide to squint hard enough to see everything as tensors! :-)