To remove the “gallery photo” from the product page, but leave the photo / thumbnail remaining in the main store page on Squarespace, you can use these CSS code.
#1. All products
You can use this code to Custom CSS box
section.ProductItem-gallery {
display: none !important;
}
#2. One Product
You can edit Additional Info
Click the Plus icon to add a block
Choose Code
And use this code
<style>
section.ProductItem-gallery {
display: none !important;
}
</style>
#3. Some specific products
You can create a tag with name: no image, then assign for products.
Next, use this code to Custom CSS box
article.tag-no-image section.ProductItem-gallery {
display: none !important;
}