View commerce product image and price fields
I'm pretty sure you'd have worked out the *the latest 3 items placed in the show_product content type* part already:


Add filters, Node: Type, Node type: show_product
Add sort criteria, Node: Post date, Sort order: Descending
Items to display: 3


For the attributes part, the tricky one, instead of defining a relationship in the existing view, you'd be better off creating a whole new view, which would list the attributes of product passed in as argument.

To make it all work together, you'll attach the latter view to the former one using one of  Viewfield (7.x-dev), Views Field View (7.x-dev) and View reference modules.

An example, using Viewfield. To the show_product node type add a hidden View field called Attrview. Set it to "Always use default value". Set the default value to the attribute listing view. The argument is "%nid". Exclude its display from node teaser, full view etc.

In the first view, then, along with Price and Image, also add Attrview as a field. Done!