We have access your website Dashboard and it looks that a plugin SG Optimizer create a conflict with the Product Image i disabled lazy load image for product image and your site is working absolutely fine.
Note: Lazy load option for the images you can find in Theme Options > Speed Optimization > Images.
We don’t have Lazy load option for all, only for the images and product elements in the WPBakery Product element settings.
Try to optimize the images on your site using the Tinypng service. At this moment images on the home page takes 3.4 MB http://prntscr.com/uztaiu and it gives not good results http://prntscr.com/uztbvs
