Hi,
Sure it is possible. Just follow my steps;
Open this PHP file:
ROOT/templates/<yourjoomlatemplatefolder>/html/com_virtuemart/productdetails/flexv2.php
and find this DIV ELEMENT:
<div class="width40 floatleft">
change it with this:
<div class="width20 floatleft">
Then find this DIV ELEMENT:
<div class="width60 floatright">
change it with this:
<div class="width80 floatright">
That's all. This change will compress the product picture to (more or less) half size of what it is now. You can play around with the numbers. For instance; you can try to change the width40 to width30, instead of width20. But don't forget the change the width60 to width70 then. You got the idea? SUM MUST BE EQUAL TO 100 always.