The only thing that I feel that Diurnal is missing compared to Nocturnal is an effect on the star globe as well; however, there are a few reasons I can think of for the current effects;

1. In astrology, diurnal and nocturnal refer to the upper and lower halves of a horoscope respectively, hence the focal animations of each sect reflect their respective halves. Nocturnal has the golden glyphs under your character, while Diurnal has the spherical glyph appear above your character.
2. Diurnal and Nocturnal reference the sun and moon respectively; in the animation of Nocturnal, as the glyph animation plays under the character, there has to be a moon of some sort, which the star globe acts as. However, in Diurnal, the spherical glyph already plays above the character, and symbolises the sun as well.
3. In both instances of the animation, the user turns away from their respective glyph; Diurnal sect makes the user look down, and Nocturnal user look up. It's easier to implement the star globe in Nocturnal because of that reason; you can't exactly have a shiny star globe looking down symbolising the sun, can you.