Earlier quoted context omitted.
I'm incredibly happy that the em dash is gaining the attention it deserves. However, if honest—I am also a little upset that the good people the comments section are tending towards placing white-space around each dash and the text it forms an abutment with. This space is not needed.
The space is conventional in Britain. Without the space looks strange to me. (Android users — try long pressing the - key in the punctuation menu.)
[1] https://en.oxforddictionaries.com/grammar/dash-and-em-dash