The Divine Beast Shield is part of the 'common Garo' gear collection sold at the Gold Saucer. It is a completely invisible shield, so it looks like you haven't got one equipped.

Currently it is only equippable by GLA/PLD, and I would like to see it expanded to be also available to CNJ/WHM and THM/BLM.

The original Garo sets are Lv60 PvP gear, so it makes sense that the shield's counterpart Heroic Spirit Shield is locked to GLD/PLD - its stats reflect that, and the other classes don't make use of shields at that level.

However, back at Lv1 (and up to Lv50), the mages do use shields, but there is no equivalent 'invisible shield' item that can be glamoured to hide them.

Thus, I would love to see it made available to the mage classes, if possible.