>>97978226>Thicker lines the closer to the camera you are is a basic principle. Like fucking 101 shit.
It's either a mistake or a stylistic choice that comes from shitty Flash animators.
The lines around a character represent the light effect around a real object's edges. In pic related of a soccer ball you can see a dark reflection on the white parts and a light reflection on the dark parts, and a very bright reflection from the direction of the light. So if you were to draw a cartoon soccer ball and had really good control over the outline, you'd make it black and white so it contrasts with the patches, and white in the direction the light is coming from.
Animators have to simplify, though, so they either use an outline that's the same color as the fill (for example look at your forearm with a white wall in the background and you'll see that in most lighting conditions there are dark edges around it), or they just use a black outline which is the simplest.
Now, strangely (or not) when you move your forearm closer to you, the "outline" does not grow larger.
'30s and '40s cartoons used line weight to actually represent something (light and shadow), but anime and modern cartoons just have "lines" with no rhyme or reason. For example the broken lip line in anime CAN represent the part where light reflects off the lip, or the bulge of the lower lip, or a lot of things, but most artists just put it there without giving it any thought.
When Flash artists zoom or scale an objects, they don't give any thought to what the line around the object represents, so they just make it scale along with the object. That's really dumb, and evidently, when you're exposed to dumb shit long enough you stop questioning it.