Everything is related to CSS customization to override the default styles used by Virtuemart 1
Basically everything is based on old tables and fixed widths, the 164px for each <td> element states the final width of the 3 columns images.
Overriding it with 33% fuild percentage will help.

The second layout needs a more complex restyling, there is a <br> that makes the button on a new line.. also reducing the width of the quantity field will help to reduce the final width.