Like most brains, the grey matter in this Series 6 is pretty inscrutable: it's encased in hardened resin, as per usual, making further exploration extremely difficult.

Update: Unless you have an X-ray machine, that is! Here's an inside look at the S6 package. If you're wondering what all the tiny shapes are, check out the original Apple Watch X-ray teardown for an explainer.

There are a few more conventional ICs piggybacked onto the package, and we can at least spot a Skyworks chip marked 239-7. The other chips are more mysterious, and none is an exact match for the U1 chip we found in last year's iPhones.

It was probably too much to ask for a labeled U1 package, but there has been more obvious printing in the past.

Sans-brains, we can see the Series 6 frame has a slightly modified footprint with a narrower lip for the adhesive gasket, which is now carefully routed around the band mechanism.

The modified case and lack of Force Touch gasket probably accounts for the fact that this year's model is a hair thinner, with overall thickness at 10.4 mm (down from 10.74 mm last year).

Apple somehow packed more battery and more Taptic Engine into a (barely) smaller design. Impressive!