I think most of Sheila's comments are very insightful.

But I disagree with the point about recognizing Clark.
I live in L.A., not far from Hollywood and Beverly Hills. Every year or two, I will happen to see someone or other famous -- at the mall, at the dentist, at the supermarket. (And I suspect that it's more often than that, but I don't always notice.)
There have certainly been some, "OMG! That's so-and-so and s/he looks exactly the same!" But there have also been a fair number of, "Hmm. They look
so familiar! Who is that?" followed 20 minutes later by, "OH!!! I Can't believe I didn't recognize him/her! D'oh!"
Some people look very similar on film and in person. Some cannot be adequately captured by that medium. I guess Lois is among the former, and Clark among the latter.
Also, Clark avoids having pictures taken of him (as Clark) rather assiduously.