Image smacking is an internal Pressidium service that optimizes your media in a lossless way. It is enabled by default and automatically performs a number of optimizations on each individual image.
You can find each media's achieved optimization rate by visiting the Media Library in your WordPress administration menu, and selecting the List icon on the left. You can also manually smack an individual image.
We strongly suggest you keep the image smacking service enabled. You can disable image optimization for an individual website by deselecting the related option in Image Optimization tab:
Open Image Optimization
Uncheck Enable Image Smacking on upload
If you want to perform a mass / bulk smacking operation, please open a support request so we can investigate your case.
Any EXIF image data are removed during the optimization process to further reduce the image size.
The optimization process is loseless so image quality is preserved.