The following Google Apps Script is designed to replace text in a Google Sheet. You provide the text you want to search for and it will replace all instances of that text (specifically the contents of that cell) with your image. You can optionally choose to adjust the size of the row/column and centre your image. You will need to ensure that whatever image you use, it is accessible online via a URL.
Note this is one of about four different ways of inserting an image into a Google Sheet.
I have a similar blog post available for replacing text in a Google Doc with an image.
Screenshot of Google logo that has replaced text in a Google Sheet |