Flag of Shalotte
Contact between Shalotte and the outside world first occurred in the 1910s, though formal contact did not begin in earnest until the late 1920s. After millennia of isolation from the outside world, Shalotte lacked a large number of institutions, technologies, and expertise required to successfully join the international community.
One of the things it lacked was a national flag. National flags had not been adopted by the rest of the world until the late 16th/early 17th century, so of course Shalottes - who diverged from the world many centuries earlier - had no knowledge of such things, and certainly hadn't designed one for their own country.
Seeing their importance to the 'nations' of the world, however, Shalottes were quick to design one. It was felt at the time that nothing represented Shalotte better than the sea; their small archipelago was surrounded by it, its weather dictated by it, and many of its people reliant upon it for wealth and sustenance. So with no knowledge whatsoever of vexillology, a stylised impression of the sea was commissioned and hurriedly sewn into flags. It has remained so ever since.
The sun hanging so low above the horizon is thought to represent the extremely northerly position of Shalotte, which is particularly noticeable during winter.