The Galaxy S27 Ultra is barely changing size, going by dummy units Android Headlines published. A dummy is a non-working model that shows a phone's shape, and these are based on earlier CAD renders (the design files used to plan a phone). This one measures 163.76 x 78.25 x 7.97mm. The S26 Ultra is 163.6 x 78.1 x 7.9mm, so you'd be hard pressed to tell them apart by size.
The vertical camera column is gone, replaced by a horizontal bar that looks a lot like the raised plateau on the iPhone 17 Pro Max. The dummies also point to the 10MP telephoto with 3x zoom going away. What takes its place isn't clear yet.
Tom Pritchard at Tom's Guide looked for those magnets on the dummy and on the renders and couldn't see them, so don't count on them yet.
The S Pen stays built in. The same leak says the design has magnets for full Qi2 wireless charging. Tom Pritchard at Tom's Guide looked for those magnets on the dummy and on the renders and couldn't see them, so don't count on them yet.
The screens hold steady too. A listing Notebookcheck found in the NBD import-export database gives the S27, S27+ and S27 Ultra the same 6.3-, 6.7- and 6.9-inch displays as this year's phones, and the new S27 Pro lands between the S27 and the S27+ at 6.5 inches. The Ultra is expected to get the Snapdragon 8 Elite Extreme Gen 6, which can record 8K video at 60 frames per second. The Elite Gen 6 listed for the Pro stops at 30.
The S27 series is expected in January. If you were waiting for a smaller or thinner Ultra, this design doesn't offer one, and the camera is the main thing that looks different. Samsung hasn't announced the phone, so which lenses are inside is still an open question.