EPS - Encapsulated Postscript
File Juicer does not contain a complete Postscript engine, so it will try to recognize EPS on its header, and trailer. To see if the extraction is successful you need to open the extracted EPS with other applications, like Preview.
EPS files can contain TIFF previews which File Juicer can extract.
Extracting EPS from PDFOne could expect to find EPS inside PDF files, but this is most often not the case as the EPS gets converted to PDF when it is saved, and becomes an integrated part of the PDF file.
To extract vector graphics from PDF you can use Preview which comes with macOS 10.4. In Preview you select the graphics and copy it to the clipboard. Then choosen "New from Clipboard" in the File menu and save the extracted image as a PDF file.