Look the Tumblr nose thing is really easy to explain. You know how in the aughts, little weeb kids would always post their animu OCs? None of them were really artists, but they could copy bases and draw that one generic animu face. Naturally they got called out, and a prevailing sentiment was that anime art is bad and drawing it makes you bad.
Tumblr nose is the counter movement to this. Primarily either the aforementioned weeb kids trying to quit their bad habit or kids just beginning artistic pursuits and seeing previous weeb kids BTFO, they instead pursue an art style that's the polar opposite. So you have huge over rendered noses instead of the no/checkmark nose my japanese animus have.
What they don't understand though is that animu drawing weebs are criticized not because they draw anime, which is a genuinely pleasant and aesthetically sound artstyle, but because they just try to immediately emulate it without having any fundamentals. So they end up symbol drawing and are unable to do anything else. The Tumblr artists are still doing the same thing, only with an artstyle they wrongfully and naively believe is superior to anime. Massive over rendered noses, hyper embellished blush and facial tint. This is also why you see so many anime redraw picks.
