In New Pokémon Snap, each of the Lental region’s areas has its own huge Illumina Pokémon. Aurus’ Illumina Pokémon is the Legendary Pokémon, Xerneas.
On your first visit to the Aurus Illumina Spot, you’ll need to take photos of Xerneas while the Illumina effect is in action. You can activate it by throwing a couple of Illumina Orbs at it, but you’ll need it to take its normal shape first.
At first, Xerneas will be a glowing orb that zooms around the area. Throw Illumina Orbs at it before it takes its normal deer-like form. Once it takes its deer form, use Illumina Orbs to make it glow.
Similarly to the Volcarona boss fight, landing hits on Xerneas can be hard because of its quick movement patterns. You need to predict where the Xerneas moves and throw the orbs ahead of its path.
Keeping the Illumina Pokémon glowing is important, as it’ll pose in new ways, use abilities, or even bring out new Pokémon to photograph.
On your second visit to the Aurus Illumina Spot, you’ll see more Pokémon there, like Umbreon and Woobat.