Flexibility, is the first, overlaying all of it. Then the broad tones of insight, knowledge - then she can slowly tease out sight specifically -
It takes a lot of very careful teasing, and someone less skilled than Celebrimbor might be forced to give up early, but... Nothing here is truly hidden, just carefully folded away, unobtrusive.
The Song laid upon it is very clearly a derivative of the ancient Songs for sight. Keen sight, far sight, seeing spectrums of light usually invisible to elven eyes, blocking other light... Celebrimbor has before now only ever seen it as something people apply to themselves in the moment, or else as a separate Song for each of many looking-glasses in a kit. These, though, are elegant - trimmed down, improved - combined, one tune rising at a time while the others fade intk the background.
(The Noldor, as a general rule, don't put very much effort into fixing their tools, especially not in ways that will mostly just reduce some hassle. Not unless it's needed for a specific project. Her grandfather had been one of the only ones who ever really bothered, and that was still mostly in response to certain repetitive tasks annoying his impatient mind.)