The box labeled "IA-32e Mode" is 64-bit mode (in their infinite wisdom, Intel chose a name containing the number 32 for their copy of amd64 mode). I think the other mode you're referring to (32-bit compatibility mode for 64-bit systems) is technically considered a "sub-mode" of that, so that's probably why they only have one box to represent both. Compatibility mode is controlled by a bit in the CS descriptor if I recall correctly.