Right now I want to represent the hidden symbolism in the figure’s using Greek letterings. Let’s begin:

φ (phi) resembles the logo for the ufo, but notice closely that there’s a ring that surrounds it that looks like ο (omikron). θ (theta) also appears as it can be mistaken as phi. One could even argue Ω appears subliminally in all three. Each letter being f,th, and o. Phi the symbol of the golden ration. Theta symbolizing death. Omicron a little omega to represent the great end. I believe this represents the alien invasion on the mountain using a sequence. For the golden ratio has specific numbers in order. φΦΟΩ

The egg has a strange crack with a Ζ (zeta) symbol which represents the “end of times”but also the last letter. Represented by the egg in the shape of ο. Together this says “the great end, last end of times.” ΟΖ

The jet pack is a bit confusing however we still get most of the message out. We get the letter s or Σ (sigma) sum of multiple terms. The head in the shape of υ or (upsilon) signifies path of virtue or vice. Again another Pythagorean reference Pythagorean branches has pointed out to you the steep path which rises on the right. The bottom of the jetpack looks like Δ (delta) and you’ll be surprised what it means. A delta is an area of low, flat land shaped like a triangle, where a river splits and spreads out into several branches before entering the sea. It’s difficult to make out, but I believe letter χ (chi) is hidden to say,"shape or arrangement." Also Christ. ζZ Xχ Yυ (coordinates) Δ.

The murals have double meanings as it symbolizes a lot in a occult way. Which is why I believe we see chi also in the bunker mural. Wether o represents time or f&th is days of the week I’m not sure. However we do know it’s there at a specific time,day,and location. If you want to get more occult maybe the (father)(son)(holt spirit) for each character? It’s all speculation from here