That is indeed a 3940 in platinum. I think it is superior to the 5140 in terms of overall balance, at least aesthetically (and I realize this is a subjective comment). Here's why:
1. Both watches use the same cal 240 movement so that negates any advantage the 5140 might have in terms of mechanical advancements.
2. At 37.5mm (sometimes listed as 39mm), the 5140 technically has more space to play with, and yet somehow it manages to squish together the "27" and "5" around the date/moonphase subdial. Picture below:
3940 on the right. Yes, the fonts are larger for the 5140, which some people prefer for legibility. But they messed up that 27 and 5, ick. Don't see it? Here's a close-up:
And it's not an upsizing of font/case versus mechanism and where subdials ought to be located thing. After all, the 5136/1J is also larger than the 3940, sporting larger fonts. And yet the squished 27 and 5 are not present:
3. I love the 3940 for its slimness - the fact that Patek can fit all those complications into a neat little profile that slips oh so easily under the cuff. The 5140 looks positively obese by comparison:
4. That's just me of course. Some people love the 5140 for a variety of reasons. And yes, the blue dial 5140P looks breathtaking in person. With that said, its MSRP of $109,000 gives me pause, especially when one can get a pre-owned mint 3940P for $55,000 to $60,000.
Is beauty really subjective? I mean...
My 3940P is 23 years old. I love it. Friends of mine have 5140s in various metals and they love 'em too. I have nitpicky complaints I outlined above, but really, both pieces are lovely. My thinking is just that if you're shelling out that much money then the piece should be as close to perfect for you - a piece that doesn't elicit nitpicky complaints.