Google has a similar products section and carousel for Google Ads sponsored listings. We have seen similar products and similar shopping related results from the organic / free listings but now I am seeing examples of a search ad carousel for "similar products."
This was spotted by Khushal Bherwani who posted this screenshot on X:
Google Ads tested a show similar button in shopping ads. We've seen shop similar features and similar products, as well as related products.
Google loves query expansion, not just for organic results but for ads.
Forum discussion at X.