When using the Marketing Content, the Flyers download as PDF files (as they contain multiple pages).
If you prefer the files to be converted to JPG you can quickly convert them and here's how:
Download the Flyer via the Marketing Content Section
Open this PDF File on your Computer
Click the "File" menu
Click "Export"
3. Change PDF to JPG
4. If you are going to Print this file change the Resolution to 300
5. Click Save