I don't know anything about LoL, but from what I just read yordle are (slightly) furry beings with a maximum height 0f 0.8 meters and most females have blue skin.
There are already examples on danbooru where the characters look more like humans and should not be tagged yordle:
post #1395740, post #1474738
Of course, we can't do an implication anyway since any kind of animalization or objectification would no longer count as yordle.
