Hi Steve -
… and from one of your other posts on the subject:
You can open the .mtl file in notepad. You will see that it references the .jpg file. so, yes, the .jpg file is used as well.
When you just import that .obj file into Rhino 5, the mesh is shown with vertex colors only. When you select that object and change the “Assign material by:” property in the Properties -> Material panel, from Layer to Object and then apply the .jpg file to the Textures > Color channel, the result will be less soft and somewhat more in line as what you see in Metashape.
You can then also play with the Sun and / or Skylight settings to throw shadows where you want.
In Rhino 7, with Physically Based materials and Cycles, you’ll see something like this:
-wim