REWA Technology posted one of the first iPhone 18 Pro teardown videos, and it shows where the Dynamic Island went. Face ID's infrared camera now sits under the display in the top-left corner, on the 18 Pro and the Pro Max both. MacRumors reports that the pixels above it carry a pattern that lets infrared light through, and that at typical viewing angles the screen looks completely normal.
The same video shows the 48-megapixel main camera with its variable aperture. The phone REWA opened has a physical SIM tray, so its battery reads 4,056 mAh, against the 4,288 mAh iFixit measured in the eSIM-only model sold in the US. One question was still open when that video went up, the modem inside the US Pro Max, and a later teardown found Qualcomm's Snapdragon X80 in it.