Redmi talks about the "trendy flat-edge body" that its Note 11 series adopts and some consumers will immediately draw parallels to the iPhone 13's design. That's both warranted and unfair because while it does adopt the flat-edge design, the Redmi Note 11S keeps some curves on the back unlike that of the totally flat iPhone 13.
Both the back and edges are made of polycarbonate material (plastic), which is coated to look like glass and aluminum, respectively. Your hands will be able to tell the difference, though, especially considering how light the whole phone feels. Plastic does have the advantage of not breaking when you drop it, so the material might be a win for those whose phones experience accidents more often than not.
The phone's flat edges are pretty normal, with your typical speaker grilles and buttons. There are, however, a few notable features that put the Redmi Note 11S above the rest.
A fingerprint sensor hides under the power button and is both accurate and fast, perhaps more so than the now-popular under-screen sensor. There's also a headphone jack on the top edge, a nearly extinct piece of hardware even on mid-range phones from Samsung and Google.