Hello,
As you want to reduce the image size of the product main image and make it equal to the right side content. It requires customization and this is beyond our limitations and support policy.
But you can try the below CSS code in Theme Setting >> Custom CSS >> Custom CSS for Desktop:
.thumbs-position-left>.col-lg-9 .woocommerce-product-gallery__wrapper {
height: 350px;
}
Remember that it might disturb some other layouts so you can use this CSS code at your own risk. Because most of the time the short description length is not similar so the image might be larger or smaller from the right hand side content.
Best Regards.
.
