As her eyes are drawn back to the sentinel, a few things come clear. Several of the glyphs seem to point to the idea that the sentinel draws it's power from Glamour - perhaps meaning that it can be fed, perhaps with dreamstones or dross.
However, there are also elemental glyphs, specifically water and earth. Perhaps the pool is a cooling agent, or is it a conduit for channeling pure power into it's form?
The most brightly glowing glyphs appear to be an emergency override, powered by it's own independent power source, which may just be the equivalent of a backup battery, for emergencies.
It seems clear that while it is a masterpiece, it is not some perpetual force - it needs it's heart to function properly, and to correctly relay energy throughout the being - much as any living beings heart will do so. Without it, it is... volatile.