Translation:You are strong, just like an elephant.
I guess it's analogous to German "gerade so wie", e.g. "Du bist stark, gerade/genau so wie ein Elefant." (Given that's not very idiomatic usage imo. The idiomatic German would be: "Du bist stark wie ein Elefant." When equal to you use "wie", when more or less than you use "als", e.g. "stärker als". Fun fact: dialectal usage in the south west prefers "als wie", "Ich bin stärker als wie du." I'm stronger than you.)
As a German speaker from the south west the "net" is an annoying fals friend, cause we regionally use "net" like English "not", e.g. "Ich bin net daheim." "I'm not at home." So I always read sentences including Dutch "net" as negations first.
Wth??? Je (etc) is NOT slang. It is NOT incorrect and it is NOT bad language habits. Who taught you this nonsense.
It is a proper official word and has been from the start. There is nothing slang about it whatsoever. It is perfectly fine in written texts. Using jij too much would actually be rude even (especially) in formal texts in formal texts, it would be replaced with u anyway. Not with jij.