It is very important to change some of the default WooCommerce settings to get the theme work as it does on the demo theme and as inteneded in the first place.
Here are the settings that should be changed:
1- On your wordpress admin, browse for WooCommerce → Settings, scroll down to the section where it says, Styles and Scripts turnEnable WooCommerce CSS & Enable Lightbox OFF and hit save.
2- By default, une boutique theme sets the proper image sizes upon theme activation. But if for any reason the settings have changed use the following image as a reference.
3- If you have installed YITH Wishlist Plugin On your wordpress admin menu you should be able to see YITH plugins menu. From there go to wishlist and under Settings Tab make sure Position is set to Use Shortcode. Save settings then go to Colors and make sure both Use Buttons and Use Theme Styles are checked, save again and you are golden. The rest of the options are up to your choice.
These were the essential settings for this theme, change the rest of the settings to your needs.