Friend's profile picture not showing in Mac mail messages

Question

So recently I updated a friend's profile in my contacts with a picture.  As expected, future correspondences through e-mail would now show his picture in the upper right hand corner of each message, as did mine when I sent one.  At this point, I only had ONE e-mail address (a Apple/iCloud address) for him but through a discussion we were having he told me that he actually used another one more often, which was a gmail address.  So, naturally I added it to my contact profile of him but then I noticed that his picture would not appear in the future emails I got from him.  I thought perhaps it was a prioritization issue within his profile so I simply reversed the order of the emails with his gmail one showing first, then his iCloud one.  Still, nothing.
So, any theories as to why this is happening?  Obviously this is NOT the end of the world but I'm still curious as how to fix it so his picture shows up in emails.

Answer 1

Yes.  In fact BOTH old and new email address are in his contact profile.  So, in the begining there was only one address, his old address which I learned he doesn't really use anymore.  So then I added the new one but kept the old one just in case.  Here is the order I kept them:
1)  old email
Then, once I learned of his new email:
1) old email
2) new email
After I learned the that the old email wasn't really used anymore, I switched the order:
1)  new email
2)  old email
I'm not sure if the order in which the email addresses are listed matters but I thought I'd mention it in case it does