Each person's trinket buff triggers an associated, hidden flag on every member of the raid. For example, when the buff from
Coraje de Khaz'goroth (Worldforger's Flame) is active, every player in the raid will gain the
Marca de Khaz'goroth flag. Once all six flags are active at the same time, the player becomes "Empowered by the Pantheon" which then triggers the secondary trinket buff.
In the screenshot above, when
Marca de Golganneth,
Llama del Forjador de Mundos (Kaz'goroth),
Marca de Eonar,
Avalancha de conocimiento (Norgannon),
Baluarte celestial (Aggramar), and
Destello de iluminación (Aman'thul) overlap (indicated by the red rectangle), the Empowered buffs activate (indicated by the yellow rectangle).
Theorycrafting Notes:
1. The trinkets seem to have a high chance of proccing on the pull and high uptime in general. This is notable as a lot of RPPM effects do not proc on the pull anymore, so this trinket behavior may be related to the new Deck of Cards mechanic, or be intentional to help ensure raids without a lot of trinkets get at least one overlapping proc to trigger Empowerment on the pull.
2. The hidden flags are not perpetual, meaning they only last as long as the trinket buff. This is an important distinction because it means all 6 buffs must be active at the same time. The Empowered state doesn't simply trigger once the 6 different buffs have activated within the raid.
This also means you will theoretically want to balance the amount of each trinket type in your raid, for a better chance of overlapping each effect, rather than simply ensuring you have one of each type which will proc eventually.
To extrapolate further - assuming these buffs are powerful enough to warrant it, using the trinkets will be necessary for organized raiding for the group benefit, regardless of personal gain. This is of particular importance for tanks and any under-represented roles in your raid group, who might otherwise want to use something else. For example, as the only Strength DPS in many of my guild's Mythic Tomb of Sargeras progression kills, I would never have been able to wear
Visión de Aman'thul instead of the
Coraje de Khaz'goroth, even if it were better for me personally.
3. The trinkets' primary procs have decently high uptime (35-50%), though it's not enough to gain Empowerment reliably without more than one set of trinkets in the group. In our raid of 6 on the PTR, we were only able to reliably proc it on the pull, as desync would then keep us from triggering it again, although the later alignment of procs were fairly close. This reinforces the idea that everyone will want to use their role's trinket with as close to an equal spread as possible, and avoid underrepresented roles creating a bottleneck. As the raid gains more trinkets, the empowerment should happen more reliably, acting as a continual soft-nerf to the raid tier.
4. IMO, Aman'thul's is problematic. While it makes sense to have 6 trinkets for the 6 titular Titans of the Pantheon, because the trinkets are equip-limited, it takes the place of one of the other role-trinkets. This means roles with low representation in your raid group (tanks and healers especially, sometimes certain DPS) will never be able to use it anyway, as they'll be compelled to use their role-trinket for the group's benefit, even if Aman'thul's were stronger. Typically, this means that Int casters will likely be the only ones with the freedom to decide, which then comes down to how the trinkets are balanced - if Aman'thul's is considered better than Norgannon's, players will fight over who gets to use it; if it's worse, players will fight over who has to use it.