This made me think that we, as a society, ought to have some sort of convention to mark AI-generated images as such, like a small watermarked symbol in a corner.
Doesn't really seem necessary unless one is claiming that the image is real. For the image in this post, it seemed obviously fake to me, so I didn't feel the need to label it as AI-generated.
Whether it's obvious or not seems to depend on a lot of factors. For instance I've seen a lot of Wittgenstein so that made me think it's made up. Someone else might think it's real.
Anyway I think you did a great job with Midjourney. Even the coarse clothes correspond to clothes Wittgenstein wore. Would you like to share your prompt?