>>42632476
This may be rose tinted by only remembering the art I liked, but I consider 2011-13 pony art to be far more heavily show inspired, often with a dash of anime. Examples include Megasweet, JohnJoseco, UC77, furseiseki, Slugbox (very anime), and No-ink. Show style art dipped as the show wore on and artists put value in having unique styles.
Other trends:
>Zoophilia (as early as 2012)
Emphasis on horsiness, including mannerisms and detailed musculature, over cartoony marshmellows. Zoofags study horsecock, phase out hvop, and ponuts slowly grow overtime. Anthro is shit talked and Eqg kills off humanization, widening divides.
>Tumblr (2013ish)
Sjws and the lgbtq focus on diversity and deviate off model as much as possible, because ugliness is beauty. They live on as the Twitter side of the fandom. Askblogs encourage tons of artist collaboration and alternate universe style characters. Grimdark's hayday.
>m-era (as the show was ending to modern day)
Mares, mares, mares. Schizos start drawing ponies that never had art before. Zoofags dig in harder than ever before.
>G5
Not a huge impact since g5 was a flop and artists tend to draw g5s in the cuter g4 style anyway, but some artists adopt right side up hearts on the bottoms of hooves for g4 characters.