In opposition to his more openly bigoted work where the noble protagonist is elevated above what Lovecraft sees as the wretched morass of daily life, ‘The Outsider’ shows the outside world as normal and happy. The scene that the Outsider stumbles across, and eventually disrupts, is described as “gorgeously ablaze with light and sending forth sound of the gayest revelry”. It is the narrator, Lovecraft himself, that is an abject, pathetic being – “a leering, abhorrent travesty on the human shape”.

More info here - https://pietersender.wordpress.com/2020/03/30/readings-the-outsider-hp-lovecraft/