THREE simple theories here WITH EVIDENCE
ONE: VERY LIKELY.
When looking at the glyphs seen on the face of mount chiliad, two stick out, because they remain unsolved. There’s a UFO with a beam coming out of it, and there’s half a UFO, possibly worn away by the weather. It’s only when you put these two glyphs together that they make any sense. The half-UFO wasn’t corroded by the weather. It’s in fact the only clue we have to say ‘hologram.’
As it’s proven that the chiliad UFO is just that, the other glyph reveals a startling truth. The chiliad UFO is a decoy… from a REAL ONE. The reason we haven’t found any new clues is because the one we’re looking for so intently has been right where we began since the start. Wherever there’s been a red eye, we’ve seen a UFO, correct? NOT a hologram, an actual, solid UFO. So here’s the thing… why haven’t we found it? Quite simply, we haven’t been looking. After seeing the hologram, everyone celebrates. ‘Woohoo, we found the Chiliad clue. Let’s move on.’
Even the fact it’s a hologram disinterests people. There’s also the fact that the location is thoroughly wrong. The chiliad UFO does not appear over the cable car stop; it’s off to the side, lined up with the viewing platform. This should, in theory, also be visible from the Galileo observatory; We can see the observatory from the platform, so why not the other way around?! But we can’t see it from there, because like the symbol, the hologram is only half a UFO, generated in the direction of the platform.
Most importantly, the UFO shown looks quite low, right? IT ISN’T. going from the sheer height of mount chiliad the damned thing is at least 100ft in the air. Therefore, we either call Rockstar’s own mural wrong, or we figure out the right answer. Someone, anyone, get airborne and start looking, WHILE THE HOLOGRAM IS UP.
Here's the mural again so you can see what I mean...
TWO: LESS LIKELY
The UFO isn’t a hologram. Simply, it has a cloaking device. As we approach, it activates. This means that the UFO is always there, and if we find the direct location of the damned thing it’ll be solid like all the rest.
THREE: QUITE LIKELY
The hologram is being generated from the observatory, hence why it falls in the exact opposite direction and is therefore visible only from the mountain. We then need an explanation for the beam glyph. This is why I genuinely believe theory one is true.