iCloud Photo Library not showing up on iPhone?

I just started iCloud Photo Library last night.

I turned iCloud Photo Library on for my iMac first and then my iPhone.

This morning it looked like my fairly large iMac library uploaded successfully.

I can see all my photos from both my phone and iMac on icloud.com. No issue there.

However, I can't see any of the photos from my iMac on my iPhone.

How can I resolve this? I turned the iPhone off and on again and turned off and on iCloud Photo Library too. Still no luck...

Also, it looks like the favorites (hearted) pictures on my iMac didn't merge over either.

Can anybody help?