This is a detail from Portrait of Alexander Pushkin (1827) by Orest Kiprensky (1782-1836), o/c, 63cm x 54cm (24 3/4 x 21 1/4), Tretyakov Gallery, Moscow.
Exquisite manicure was a fashion among men in the age of dandies. And even then it was criticised as a mark of shallowness.
Pushkin referred to the criticism in his classic novel in verse Eugene Onegin
A man who’s active and incisive
can yet keep nail-care much in mind:
why fight what’s known to be decisive?
custom is despot of mankind.
(in Russian: "быть можно дельным человеком и думать о красе ногтей")
The verse is often quoted to say: don't judge people by their appearance.
from Eugene Onegin, Chapter 1, XXV.
Translated by Charles Johnston.