Serendipity is a difficult concept to visualize. For me it means being at the right place, at the right time, and being lucky enough to capture something unique. Some of these entries are set up shots trying to illustrate that concept, and some record a serendipitous moment experienced by the photographer themselves. This is a lovely sunset shot, but not unique enough to qualify for serendipity.
Does this fit the challenge? I think your score will suffer from the lack of obvious serendipity in this shot. Apart from that, it is good. The dark wisps of cloud in the top-right clash with the sky a bit.
Mm yes... the sun sets everyday... while it's an ok shot... not really anything serendipitous about it. Just a plain ole sunset... Kinda... boring? Not trying to offend you, just giving my honest opinion :)