How to change the widget image size in WP Product Review

If the top review widget is showing product images in small size like 50px; add the following code to  functions.php of your child theme to change the image size. If you don't have a child theme then you can paste the below code snippets into the custom plugin created using the instructions here.

add_filter( 'wppr_review_image_size','use_image_size',20,1 );
function use_image_size( $size ) {
    return 'thumbnail';
}