It's implying that there's some sort of hypocrisy or logical contradiction with Christians suddenly caring about pronouns being correct when it applies to God. But that entire premise is wrong, because as someone else eloquently stated, they never claimed not to care about pronouns, in fact they care about them probably more than most transgender people. They just care about them being their version of "right". The post is very clearly meant to be some sort of gotcha or serve to Christianity. But there is no gotcha, so the whole post is stupid. Really picture the exchange:
A: "I love God, I'm so thankful for how she's blessed me."
C: "She? God is a man. He blessed you."
A: "Ohhh, so now you care about getting pronouns right, but not for someone like Elliot Page, huh?"
C: "No, I always care about getting pronouns right. That's why God is a He and Page is a she, and it pisses me off if you say either of those differently"
???
So with that in mind, we can see this post is just someone owning an imaginary strawman.
But to the Christians, misgendering is defined as calling someone by the pronouns they "actually aren't", so they would consider he/him pronouns to be misgendering Page. Their notion of misgendering has nothing to do with what the person wants to be called, it has to do with what they fundamentally are. So from that point of view, there's no contradiction in their reasoning. It's internally consistent, and so there's no "revelation" (ha ha) where they're trapped into looking like a fool as this imaginary Twitter post scenario implies. So this whole hypothetical demonstration of calling God a girl still goes nowhere. Go back to my initial dialogue. See how there's no next response for the atheist, how it ends with the atheist having nothing to say? That's why the Le Epic Win in the original post is not what it's presented to be. Its a bad argument. The argument is implicit, but it's there. It's the entire content of the post.