Confustion between Nokia Account and Microsoft Account

[upsidedown]

I have a Lumia 928 and recently purchased a Lumia 2520. When I set up my Lumia 928 last year I assigned a Nokia Account and I assume this is used for Nokia apps such as HERE, and Nokia music. I recently purchased and set up a 2520. When I went to enter my Nokia account it stated that I could 'link' it to my MS account. But now the devices do not have alignment between the shared apps.

Does anyone have any clarity as to how the Nokia account is leveraged in the set up vs the MS account, specific to the Nokia specific apps.