It is certainly a delusion that they are snow cornices given the maximum of 5 mm of snow per year on Mars and the decades of looking for water on the surface of Mars that missed this obvious "snow". They may be actual salt. Or "salt/iron-sulfate". Or overexposed pixels. Or exposed bedrock reflecting light. It is up to you to provide the analysis that shows hat they are snow or to ask an expert. That is not my job.
I go for the brine seeps as the mainstream but once again this is the mainstream idea - you are supporting and hardly defending an ATM idea.