Edit: answering my own question, https://blush.design/ (link found on the humaans page) has things that look a lot like that. So that's probably the origin. There are multiple artists listed on the website (https://blush.design/artists) but I can't tell which one did what. I can understand that it's very practical to be able to mix and match parts of images like that, but I personally find them very unappealing. But seeing how much they are used, maybe most people like them?