tractate brachot - Reciting the blessing of "Meshaneh Habriyos" ("who makes creatures different") on human beings

Based off the gemara on Berachos 58b, the Shulchan Aruch in Orach Chaim 225:8-9 writes:

for seeing a person with a dark, very red, or albino white complexion- or a person who is bent over because of obesity, a midget, a person with a lot of warts, a person with hair that clings to each other...

... for all these one should recite the blessing of "Meshaneh Habriyos" ("who makes creatures different").

Question:

As this beracha would seem to be offensive and could potentially cause pain to another human being, how can one understand such a beracha?