Hi Hari,
In my case, I do not see the magnifying glass button or the option to open the lightbox for the individual product picture as mentioned here :
Under Customer View in https://docs.woocommerce.com/document/adding-product-images-and-galleries/
“Upon clicking the amgnifying glass, a Lightbox pops up so customers can see a highlighted closeup of the image against a dark background and, if there is one, view the Gallery as a slideshow”
Why is that option not available for me?