Jule's character has always been about self-destruction
When we first watched Season 3 Episode 4, I think all of us were deeply disappointed by her actions. "We were rooting for you, we were all rooting for you, how dare you?" We want to see Jules conquer her feminity, make it as an artist, so her "temper tantrum" in episode 4 felt very out of character and felt like a character assassination.
There are a lot of writing choices in Season 3 I don't agree with, but looking back, I realised this moment may not be out of character for Jules. Jules is deeply self-destructive, her childhood is laced with self-hatred and self-harm, Rue narrates in Season 1 episode 4 "Jules had many coping mechanisms, none of which were healthy" Her self-destructive tendencies were masqueraded as "conquering feminity". She matches with weird men on Grindr and goes to dangerous places where nobody would ever go to. Perhaps her self-destructive tendencies were a coping mechanism, perhaps it's just an instinct, or perhaps she does these things because she's deeply afraid she will never be loved for who she truly is. The whole time she was with Anna in Season 1, she imagined Rue as her, only to put a barrier between herself and Rue once she heads back. Why did she do that? I believe she did so that she would not have to be confronted with the idea of losing another person she loves (like her mother in the special episode) to another drug binge.
I don't remember too much details in Season 2 since I find Elliot really "meh" as a character. But I believed that she started affair with Elliot during her relationship with Rue because she had mistaken Elliot and Rue for being in an affair together when they were just doing drugs. She self-desructs and sabotaged her relationship yet again because she was so afraid of the idea of rejection. You won't ever be confronted with the idea of rejection by the other party when you choose to sabotage the relationship first. When Elliot confesses that he and Rue were doing drugs for two months we see her relapse into self harm.
Which brings us to Season 3. She starts an affair (yet again) with a married man as his sugar baby, even though we get the idea that she bore feelings for him while he just see her as a sex object. He gets her to do extreme life-endangering stunts, and it ties back to her meeting unknown strangers in dangerous places for a hookup.
We can all agree that the painting she drew for the TV network was completely unprofessional and unfit, and I think there was miscommunication from both sides (Lexi told her to just do whatever she wants). And Jules, who just dropped out of Art School, and was probably not lectured on Standards and Practices because she dropped out, put her own soul into that art piece. When I view that artwork, I don't view it as sexual or erotic, rather the artwork depicts freedom. Upon closer inspection, none of the people in the artwork were engaging in sexual acts, they were doing somersaults, laying in the grass, and being completely happy with their own bodies. Even though I agree the nude painting wasn't suitable for network television, nudity doesn't have to be inherently sexual.
When we tie back to her dilemma in Season 1 about "conquering feminity", her childhood flashback about hating almost every part of her body , the painting was her finally embracing herself for who she really is, accepting herself and not giving in to self-hatred.
When we look back at her self-destructive coping mechanism after she was rejected by the Network TV, it ties back to Season 1 and 2. She constantly sabotaged and destroys her relationship with Rue so she wouldn't have to be confronted with the idea of Rue relapsing to drugs or Rue starting an affair with Elliot. She destroyed an amazing job opportunity and possibly her friendship with Lexi so she wouldn't be confronted with other people's rejection of her expressing her true self, through her art. It was immature, it was hard to watch, and I deeply wished Jules continued with her therapy. I still love her deeply, and I will continue to root for her not to relapse into her self-destructive behaviours, but I'm afraid that she has drawn herself into a corner with her self-destructive behaviours