Ceiling = triangle
The downward hand makes Pyramidal Resonance. Its band is green, and its Witness-test pattern is the triangle.
Salvation's Edge

Enter a hand's telegraph and shoot its wrist to reveal the band: green Pyramidal, red Hexahedral or yellow Spherical.
Collect the matching Resonance from that hand type, re-enter its attack and break the band to gain Glyphbreaker.
Stand in the central Pool of Light and shoot one chest glyph. Breaking glyphs also spawns Subjugators on both sides.
Break all six chest glyphs before The Final Shape expires; the center platform then rises for damage.
During damage, move off each diagonal sweep and jump the full-platform blast on the eye flash or audio cue.
The selected map and this mechanic brief stay on the same encounter.
ENCOUNTER 05
The Witness loop is a translation test: hand position tells you the attack, the attack gives Resonance, and the band converts it into Glyphbreaker.
The downward hand makes Pyramidal Resonance. Its band is green, and its Witness-test pattern is the triangle.
The side hand fires Hexahedral beams. Its band is red, and its Witness-test pattern is the square.
The upward hand sends Spherical bee zones. Its band is yellow, and its Witness-test pattern is the circle.
After breaking a matching wrist band, enter the central Pool of Light and destroy exactly one chest glyph. Repeat until all six are gone.