When using product layout, we will pick random products to collect reviews. This default behavior is generally used for previewing reviews collector page. In actual production, you should specify url parameters to tell us which products you want to collect reviews.
product_ids=PRODUCT_A_ID,PRODUCT_B_ID with comma-seperated ID values for list of products you wish to collect reviews.
Alternatively, you can pass
product_external_ids to retrieve products using product IDs from ecommerce platform.