Sankey diagrams of AAPL, GOOG, MSFT, AMZN income statements

It's kind of odd, when put together, that the Apple "profit" section looks a lot smaller than other "profit" sections, but is in fact the largest.

I guess the scale is only within the individual diagrams, but then placing them together side-by-side makes it look a little misleading to me, YMMV.

What heading is AMZN’s R&D under?