While there are a lot of Zoom Backgrounds, I’ve had the devil of a time figuring out what formats actually work. One thing is for sure: the default format that an iPhone produces is not valid. So with some trial and error and looking at the formats of valid files, it looks like it wants something that is 1080p or less and it wants an H.264 file. The default output of an iPhone is a HEIC encoded (that is X.265) file so that is the problem and of courses I had already posted, this, but it’s reminder for everyone, you can just use Handbrake to do the conversion and all is well!