To fix the blurriness, you'll need to edit the style the media widget is tied to.
Note: If this style is being used on many other pages, you may want to copy the style so it only affects this one page.

To fix the blurriness, navigate to:
  1. onMessage > Website > Site Name > Styles
  2. Click the Edit button next to the appropriate style
  3. Change the Default dropdown to Widgets
  4. Click the Media icon
  5.  Select the Cover Photo
  6. Click the Advanced button at the bottom left of the screen
  7. Paste in the code max-width: 50px; (or however large you want the photo to be)
  8. Apply Changes