I think that would be very useful, and I have done it in at least one of my reviews. That said, in the reviews where I didn't make such a comparison, none occurred to me. If I try to force it, I am afraid I would come up with:
Provider resembles a shorter, less buck-toothed Nicole Kidman.
Provider looks like Natalie Portman had a genetic love child with Jane Lynch.
Provider resembles what I think a young Barbra Stanwyk would look like if she were in color, and of Chinese ancestry on her mother's side.
Hmm, this could be fun.
Posted By: bob175us
A lot of attributes are important to me. Among those, I am a sucker for a pretty face. Of course, what I like in a face may not be what someone else likes in a face. And while I can mention specific attributes of a face that I tend to like, more than anything else, it is the overall view that matters.
I see that few providers show their faces in pictures and I completely understand the privacy concern that lies behind the reluctance. So am not going to request face pictures.
Absent a face picture, what I have liked in some session reviews and in some web site profiles of providers is a description of prominent features of a provider's face, combined with a statement that is along the lines of one of the following:
"Provider P's face reminds me of X"
'Provider P's face has a likeness to a combo of that of X and Y"
"Provider P's face a likeness to Z except for feature D "
...
where X, Y and Z, even if not celebrities or models or people whose pictures I have not seen before (btw, I have not seen pictures of many celebrities and models anyway

), are people whose pictures are available on the Internet with some search.
Am I missing something?