What does it look like when printed or exported to PDF?
What does the Info panel tell you about Actual and Effective PPI?
What does the Links Panel tell you about where they are linked to?
Are you sure they downloaded the files to their computer and didn't open the file through some remote access direct to the server?
Printed and exported PDF versions appear fine. On one of the pixelated images the actual PPI is 300, the effective is 114. (But it displays fine on my screen, with the same PPI.) The link locations are in a local folder where the package was downloaded on the harddrive, and are being accessed on the machine itself, not from a server.
Would embedding the images in the INDD file help?
Thanks for your help!
No embedding would not help at all. It's the same image.
I suspect it's something to do with their graphics card and or settings on their machine. Can you get their specs?