Algernon, in his infinitely contradictory ways, was summoning Lane's moral values and condemning them whereas he had no values of his own. What is funny about that statement is that it was the aristocracy (back then) who was viewed as the people whose job was to "set the example". Since Algernon cannot possibly do that, he once again twisted it all around and basically said about Lane's class what people said about his "What is the value of the Lower classes if they cannot set the example". As far as materialism and superficiality, leave it to the Victorians- they were experts in those matters.
I don't know what examples the aristocracy could set for poor people other than maintain the status quo.
Isn't it representative of the sometimes superficiality of life where materialism and good looks determine the success or failure of people? I think it is.