I cloud storage and upload

I have annual membership. My I cloud storage shows 12.8 GB remaining. Frame is MC227

When I signed onto my PC at my.meural.netgear.com I see my photos and a mark on the picture “ On Meural “. The problem is when I click on a picture that I want to send I get a message “ failed, your canvas out of space”. I did confirm that free space is 0 storage . But if I go to + sign (;upper right )and click upload it opens up a screen with files to upload and I click on Photos and up comes my Library. Once there I select pictures and they are sent to Meural.  How can this be ? If the 4gb on Meural is full why can’t I cloud storage fill in?

Also, 

When I use my I phone or I pad to access the Meural  I see many linked albums and other groups ( does not say linked). CAN you clarify?

Thanks