Gaming Swapnote Blurry Lines

[Kayouu]

Has anyone noticed the lines they write in Swapnote are somewhat blurry while in 3D mode, both 3D and non 3D lines. If you slowly move the slider the lines will go blurry to clear than back.
Kinda odd I think. What's everyone else think?

 

[nintendoom]

The lines get blurry when you're in 3D mode.
IDK why.
To add a "Shadow" effect, maybe?