My question is about retrieving a URL for an image that is embedded in a cell and doesn't have anything in the formula for that cell, i.e. the formula is empty. Any call to Google Sheets API returns a blank. (This was asked in the last comment of this question
Here's an example of a sheet like that: https://docs.google.com/spreadsheets/d/1s832kuJt6jrfohHx9CsWQDfRjJghMBOOnn182DdBafg/edit#gid=922381068
