When you use bulk import tools you, maybe, don’t have product image. Usually, this happens when you import different coupons and offers. Very often, coupon feeds don’t have any product image.
So, for this, you may want to show brand logo image for such posts. (How to add brand (store) to post).
For this, Download zip file
Then, go to Plugins – add new and upload this file, then activate it (RH Fallback image plugin).