Originally posted here, then later in higher resolution in the official art channel here
Here are the known clues which are immediately apparent in the image:
1. αίθουσα
There are three groupings of characters hidden near the bottom of the image (above the footer). These were found in three separate posts (1c, 1a, 1b)
These characters were determined to be approximately “ai0ouoa” in this post.
They were then pinpointed to be αίθουσα in this post and this post .
αίθουσα was then connected to Aethusa in this post.
2. Aethusa cynapium
In this message (image of message: Missed_Clues_T1A.png) Rob pointed out a connection which was never made regarding a Aethusa plant hidden in the image.
On the second image, there was two prominent flowers that are not visible in the trailer present. The flower is called Aethusa cynapium (Fools parsley). This is a dangerous flower and the latin name is derived from the Arab word ‘ai’ what means burning, since the plant gives you burning pains.
3. Poseidon Trident Symbol
Poseidon is the father of Aethusa.
I believe this is close to if not the exact image used:
