The term refers not so much to the form of the Mass but the style in which it is celebrated.
It will the be OF but instead of a loud organ, big choir and large processions it will have quieter and simpler music, perhaps a darkened environment with more candlelight and a more overall serene or mellow bearing to it.
It’s very relaxing and it is a wonderful way to spend time with our Lord. Some people like the big fancy stuff, others like the plain and simple. It in no way is a different form, just a different way of celebrating it.
