Humans have a saying that "Beauty is in the eye of the beholder", which basically means that if you think it's beautiful, then it is beautiful. The elfin version of this saying was composed by the great poet B.O Selecta, who said "Even the plainest of the plain shall deign to reign", which critics have always thought was a bit rhymey. The dwarf version of this maxim is "If it don't stink, marry it", which is slightly less romantic, but the general gist is the same.
Eoin Colfer (2014). “Artemis Fowl:”, p.865, Penguin UK