In Miles' visual examples of cards, he presents them in portrait (rather than landscape) orientation.

This goes against the broad grain of most standard card index filing systems of the time, but may be more in line with the earlier French use of playing cards orientation.

His portrait orientation also matches with the size ratios seen in his Card-Tray suggestion on p187. https://hypothes.is/a/llEgpIf4Ee-dVfcaIGUryQ