Both DISTRO_FEATURES and MACHINE_FEATURES work together to provide feasible support on the final system.
When a machine supports a feature, this does not imply it is being supported by the final system because the distribution used must provide the underlying base for it.
If a machine supports Wi-Fi but the distribution does not, the applications used by the operating system will be built with Wi-Fi support disabled so that the outcome will be a system without Wi-Fi support.
On the other hand, if the distribution provides Wi-Fi support and a machine does not, the modules and applications needed for the Wi-Fi will not be installed in images built for this machine, though the operating system and its modules have support for Wi-Fi enabled.