Adobe PDF Pack is a bundle of Adobe Document Cloud services. With it, you can easily create, combine, sign, and send PDF files online. You can also convert PDF files into editable Word or Excel files.
What you are looking for, can not be achieved with the PDF Pack subscription. PDF Pack doesn't allow you to convert .pdf to .jpg file using desktop application Adobe Reader DC.
However, it supports the pdf to jpg conversion on web- Adobe Document Cloud
For more information please refer- How to Use Adobe PDF Pack
Adobe Acrobat DC subscription would help you in this type of file conversion. Related help article- Answers to some of the most frequently asked questions about Acrobat DC
Hope this answers your query.