Changing the display size of images
You can change the display size of an image within a View with the .gv-image
CSS class. For example, if you want your image to be resized to 300 pixels in height and width, you'll specify the height and width like so:
.gv-image {
width: 300px;
height: 300px;
}
If you're not sure where to add custom CSS to your website, please see this article: Adding custom CSS to your website
If you need to resize an image to reduce the file size, the GP Media Library plugin can help you do this.