Photo rejected b/c 'excessive post-processing and/or noise'

Hey guys,

totally new here, checked few other topics but im still a bit confused as to why one of my photos was rejected while another, similar one was accepted.
The explanation was that 'during our review we found that it features excessive post-processing and/or noise'

This one was rejected

The one below was accepted

What i find weird is that both have a ton of noise to them, both however lack any kind of editing or effects, so what is the limit of acceptable noise, thats the cause i suppose?