I assume the none "scary" kind In reality i think its short-hand for no beard or prayer robes... not my words i should add.
Most Muslims that don't have a big beard and wear robes (and that's most of them) certainly wouldn't describe themselves as "secular Muslims" and it would be wrong to describe them as such.
Nor makes it any sense whatsoever to call big-bearded types "scary" even in cheek.
Now, big-bearded types under 35 who you know aren't clerics or training to be clerics... you might have a point.