Just try few times, please. Clicking in the matrix or on the three dots and outside the matrix after that, will make this (at least for me). On the other hand, what's the point of "Show indices" when I can see this picture (see the picture). Another confusing thing for me is that when I make the output of the matrix A twice, sometimes (can not define when) resizing one of them will make both to be resized at the same time???