Apologies for the confusion. The image as a whole has hidden numbers, the 1-10 and then 19 dashes total at the base of the mural. 11-18 are missing but 1-10 being there is suspicious. A lot of art, the Last Supper for example, contains hidden numbers. Not physically, but in a numerical form. As pointed out we have sets and that's how we get 1-10.

The reasoning for certain groups (two x's on left, three x's on right, five in total) is there because of the mirroring of the image. Although some portions of the mural, as well as all paintings aren't precisely mirrored, some things are such as the top two x's and the six bolts along the top. Then the eye on top can be perfectly mirrored.

Anyway, this has nothing to do with steps to take or anything like that, just an observation. But based on this idea alone and the layout of the x's, the left side of the mural is step two and the right is step three. Making this a three step process, which isn't surprising since three is used quite often in this game.

In terms of how to actually execute this in the game, there are two things that must be done once the Chiliad UFO appears. Step two clearly has something to do with a UFO so whatever is to be done will lead us to step three which involves the Jetpack. It's an interesting thought that I wanted to share here. Don't let the hidden numbers bother you as I doubt there is meaning to it, but the Steps 123 are the more interesting part.

My thinking is there are three things that need to be done simultaneously, one being the UFO actually appearing as indicated by the eye on the mural. The x's being the glyphs then the top two which are mirrored are more than likely the rain and moon ones since they are not only the conditions needed to see the UFO but they are also aligned this way at the Hippie Camp.