That link contains the most detailed biographical information I could find in a quick Web search. According to it, Phyfe did pastel portraits of Hollywood and Broadway stars after the war, then shifted to photography starting about 1926. Pastels were the fashionable portrait medium for movie fan magazine covers during the 1920s and early 30s, perhaps because smooth blending was possible so that faces of female stars generally looked more flattering than if done in oil paint. Plus, pastel portraits could be made relatively quickly and cheaply.
It seems that Phyfe was something of an eccentric who nevertheless was acceptable socially. And his approach to portrait photography of women was practical: scroll down the link for his hints to sitters.
As best I can judge, his pastel portraits were about par for the fan magazine cover course, lacking the pizazz of masters of that small art such as Rolf Armstrong. And his photos also strike me as being competent, but not in the Cecil Beaton or Edward Steichen league.
So that we have below are decently made period pieces, which make them interesting to me and perhaps you.
Phyfe was one of Florenz Ziegfeld's photographers by 1930, but he made this pastel of Ziegfeld's wife Billie Burke for what seems to be a Follies promotional piece or program cover.