I think they may refer to the actual Amazon page, found under "Editorial Reviews". For example, from a random book I found. https://www.amazon.com/gp/product/

I think they may refer to the actual Amazon page, found under "Editorial Reviews". For example, from a random book I found. https://www.amazon.com/gp/product/0385542364/ref=s9_qpp_gw_d99_g14_i4_r?ie=UTF8&fpl=fresh&pf_rd_m=ATVPDKIKX0DER&pf_rd_s=&pf_rd_r=2VTHTMFBDX8J4H9DN6BZ&pf_rd_t=36701&pf_rd_p=6aad23bd-3035-4a40-b691-0eefb1a18396&pf_rd_i=desktop https://www.amazon.com/gp/product/0385542364/ref=s9_qpp_gw_d... Editorial reviews by Oprah, someone from the NYT, People, NPR etc.