It is slightly taller than standard 480p (which is 640x480) but not as wide as 720p (1280x720). A 640p file would likely have dimensions around 854x640 or 1138x640 (depending on aspect ratio). This suggests:
While various versions circulate online (such as the 640p WEBDL you mentioned), the official source typically provides high-definition streaming for members. Content & Plot Overview ghosted digital playground 2024 webdl 640p full