(1,1) (1,2) (1,3) (1,4)
(2,1) (2,2) (2,3) (2,4)
(3,1) (3,2) (3,3) (3,4)
In the above diagram, the (A,B) pair shows the MATLAB indices to that position in the array. The first index is the row number and the second index is the column number. But if you now take that array and put it on a standard cartesian axis, changes in height correspond to Y coordinates and changes in width correspond to X coordinates. So the first coordinate of a MATLAB array corresponds to Y and the second to X. The datatip is showing the (X,Y) pair because that is what people are accustomed to seeing labels as, but (X,Y) pair is not the indexing scheme that MATLAB uses.
The image is not rotated: the datatip is not showing the index order.
