I believe Sharingan and Byakugan users can distinguish between Elemental Clones and the Original but not SHADOW Clones and the User.
Shadow Clones are inherently different from other clones. But Elemental Clones are composed of the element, and I believe that composition allows them to be detected by chakra vision users. Now, if it's an Elemental Shadow clone tech, like the Lightning Shadow Clone tech Kakashi uses, it would still fall under Shadow Clone, meaning Sharingan and Byakugan users couldn't tell the difference.
If I recall correctly, Hashirama used Wood Clones, not Wood Shadow Clones, so they were composed of Wood Release (Water and Earth). Given that, it makes sense that Madara could see water and earth chakra surging through Hashi's clone to tell it wasn't the original.