Google is experimenting with adding favicons (brand logos) to Shopping ads. This update, spotted in live search results, mirrors the current use of favicons in free shopping listings and search ads.
Ginny Marvin from Google confirmed the test on X, stating that it is an experiment to show favicons in Shopping ads, similar to how favicons appear in free Shopping listings and Search ads.

The goal seems to be enhancing brand recognition and trust directly within the ad unit, helping users visually identify retailers more easily as they browse product options.
Read all about it here: Google Testing Shopping Ads With Favicons.