Raise questions above in the Issues area
- Uploading image https://help.ghost.org/hc/en-us/articles/223237408-Upload-Images - nothing on max image size, but limiting to a max browser res and width size makes sense. Aim at no more than 1920 px width. TBC.
Ghost FAQ https://help.ghost.org/hc/en-us
Using Ghost https://help.ghost.org/hc/en-us/articles/224938667-How-to-Use-Ghost