Google Ads added more algorithm signals (robot food) to Performance Max campaigns.

Search themes in Performance Max allow you to provide Google AI with valuable information about what your customers are searching for and which topics lead to conversions for your business.

It’s keyword (up to 25) targeting for PMax. Both a way to help bridge the gap in instances of minimal or missing data for Big G to pull from your site and (I imagine) to make more search marketers comfortable with the new campaign type.

It’s found via the Signals card in a campaigns asset groups tab.