When I upload an image, I get 5 additional sizes. Three of them are the ones identified in WordPress dashboard > Settings > Media:
200 (thumbnail)
500 (medium)
900 (large).
In addition, there are two others made: 768 and 1536 (of course only for very large images). I’m trying to figure out where they are defined. I have no such functions in the child functions.php. Does GeneratePress do that somehow?
Nevermind, apparently they are defined in wordpress core. I found 768 as “medium-large” in /wp-admin/includes/schema.php, then a 2x medium-large in /wp-includes/media.php. It’s all very mysterious.