If you search for the heading "All-New Design Enabled by M1" (near the beginning), then there is an image that shows the layout of the small keyboard. Further

If you search for the heading "All-New Design Enabled by M1" (near the beginning), then there is an image that shows the layout of the small keyboard. Further down, under "Touch ID Comes to iMac, Along with Color-Matched Accessories", there is a gallery, and the third image is of a full-size keyboard.