Stable diffusion is like any other tool, but I'd recommend asking before using anyone's art. I'm fine with the derivation, but other artist might not be.
I'd say stable diffusion doesn't work here, but then again I'm because I made the original one.
Sure this has finer detail but the eyes don't match rest of the detail and there's few other anomalies common to stable diffusion.
The inaccuracies that I made in the original drawing pop out more in the detailed one. Also the fine detail sets higher expectation that doesn't match the very simple pose.
Again, this is just my subjective opinion.
There's still times when stable diffusion can work, but I feel like it has to be intended from the ground up because you have to take account the limitations of the tool.
and yeah, there have been some recent issues with people uploading illegal content to this site which is probably why file uploads won't work well. Best to use an image hosting service like imgur, FA, deviantart, etc. and just put in the link.