Most of the difference is explained by an increase in revenue while holding expenses constant: "Other Bets, which includes the Waymo self-driving car business

Most of the difference is explained by an increase in revenue while holding expenses constant: "Other Bets, which includes the Waymo self-driving car business and the Verily life sciences unit, reported revenue of $657 million, up from $226 million the year prior. Its loss narrowed to $863 million from $1.24 billion." So revenue up 400 million, and losses dropped by 400 million.