Comment by rrr_oh_man

AI / scraper bots. Headless Chrome and Puppeteer default to 800x600 iirc.

Edit: Yup, seems correct. See Puppeteer docs [1]. Several issues suggest the same for Chromium. [2]

[1] https://pptr.dev/api/puppeteer.connectoptions

[2] e.g. https://issues.chromium.org/issues/40601921