When you click on the product name, the product, description, and full-sized picture are displayed. Most shopping cart programs allow you to set attributes for a product, such as size or color. Miva stands out by allowing you to specify as many attributes for a product as you desire. Conceivably you could designate size, color, and fabric, and include a different price add-on for each attribute. The product would have a single SKU, but the extra amounts for the attributes are totaled separately in the shopping cart.
Selection can be by radio buttons, a drop-down select list, or checkboxes.
Or the customer may enter characters into a text entry field. Attributes can be specified as required. The downside of the attributes feature is that I could find no way to upload products together with their attributes, or to quickly add pre-configured attributes to a product. Each attribute needs to be set up manually using the browser interface. Just hope that most of your products don't need attributes.