However, given the sheer amount of Persian culture in Amarr, I think its reasonable to play up those elements much more than we do. But that is a much bigger argument. I mostly just thought this was a cool thing to see.
I'm all for playing up the 'persianity' of the Amarr, I still don't think that the depiction here leads one to assume Sassanid Zoroastrianism. First, as far as I know Sassanian Zoroastrism was probably decidedly dualistic. The Amarr are not. Second, Sassanian Zoroastrism was tolerant to other religions within it's sphere of influence (safe for christians for some time, but that was due to political ties between Christianity and Rome). The Amarr are not. And third, Zoroastrism in general was (and is) opposed to the idea and practice of slavery, though the commitment to this varied. Amarr, quite blatantly, are not.
That said, the picture really only intimates some symbology in association with light. This, alone does indicate nothing. And even if we assume the 'persianity' of the Amarr as an additional premise (which we must, if we want to get with our interpretation into the direction of Sassanid Zoroastrism) then we have to acknowledge that Persian culture has far more to offer than merely Sassanid Zoroastrism in regard to religions:
The better part of the last two millennia Persian culture has been predominantly Islamic. Judaism, Christianity, Manichaeism, Baha'i and other religions all played a role in the Persian cultural space. Not to speak of all the variations of Zoroastrism itself, from Achaemenid era Zoroastrism, through Sassanid Zurvanism and Persian Mithraism up to modern Irani Zoroastrism.
So, while I am in favor of taking inspiration from all of these (as I did, actually) I don't think that the picture or anything else means that we should take Zoroastrism as a 'model of the Amarr religion'. Christianity, by the way, is in my book an equally bad choice. Just as any other real world religion.
I honestly believe it is far more fruitful to look at the PF and characterize the Amarrian religion in terms of religious studies and philosophy of religion, assuming that it is as unique as any extent religion, rather than starting from an already skewed viewpoint for the sake of familiarity. If people would more broadly adopt this, there would hopefully be less IC discussion turned into OOC attacks on RL religion(s). Also, I think it would lead to appreciating Amarr reliogion as something unique, which we really should, imho.
P.S.: It is most definitely a cool thing to see. And I would like to see much more of it, as well. As Adreena said: Every Amarrian ship a book/icon! \o/