Add photos, movies, and files in TextEdit on Mac
You can place photos, movies, and files (such as another text file, a spreadsheet, or an app) in rich text documents. When you add a file, it appears as an icon in your document.
In the TextEdit app on your Mac, do any of the following:
Drag a photo, movie, or file from the Finder to your document.
Choose Edit > Attach Files, select the photo, movie, or file, then click Open.
To open a file you attached, double-click the file icon. To save the file you attached, drag its icon out of the document. If you add a file to your document, the size of the document increases by the size of the file.