It's totally possible to send some big "special vibe" even without having meant it (just think to MLP). Just like good intentions could end up capsized even just by the wrong lighting or whatnot (boy haven't I heard hot takes on the movie passengers).

But you can't write about some specific aspect of reality (be it physics or psychology) completely out of your ass, it would be akin to the famous monkey writing a poem by blindly typing on a keyboard.

This is only seldom a problem for fiction, since most of times you are writing about something completely made up happening to somebody completely made up (you just have to clear the bar of understanding basic human interactions) but if you shift the focus from the story itself to how it could relate to an irl topic, the lens is dramatically different.

In this case we know the author's understanding of christianity to be basically nonexistent (to the point that if it had happened the other way around, we'd be calling for that to be insensitive and trivializing). The symbolism was literally there just as a sort of clickbait. You can argue the cross that was originally drawn with no particular meaning suddenly has one given the context of the scene, but... uh, what's even the meaning of that meaning then? How much are you actually still analyzing the medium itself, as opposed to just your own experience?

Not who you are replying to, but there is some interesting theory on this related to "death of the author". It is not a clean-cut question, with lots of fascinating implications.