This means that when the page experience report and performance reports are filtered by "good page experience," you may notice an increase in desktop impressions.
Google clarified their all but clear announcement saying “Search Console now logs impressions in the Page Experience report for additional desktop features, such as Top Stories. As a result, you may see an increase in your desktop impressions in the Page Experience report, as well as in the Search and News performance reports when filtering by the “Good Page Experience” search appearance.”
Some desktop features were not tracked by Google in the page experience report. You may notice an increase in impressions beginning on or after May 13th, now that Google is tracking and logging those impressions for additional desktop features for the page experience report. When you specifically filter those reports using the "Good Page Experience" search appearance, this can also have an effect on the Google Search Console Search and News performance reports.
What to keep an eye out for If you notice a spike or increase in impressions beginning on May 13th, you can drill down and filter by "Good Page Experience" search appearance in the Search and News performance reports to determine whether this is likely due to the new logging of additional desktop features.
Google has always logged those impressions in the other reports, but not specifically for when it comes to desktop page experience.
Sources:
Schwartz, B., 2022. Google Search Console page experience report now tracks more desktop search features. [online] Search Engine Land. Available at: <https://searchengineland.com/google-search-console-page-experience-report-now-tracks-more-desktop-search-features-385195> [Accessed 17 May 2022].