As Gwen squints over Thistle's shoulder, she notices that some of the swirly bits look kinda like old runes she has seen in other fae workings, but none of them are quite right. Maybe just a coincidence.
But Thistle?
Thistle looks at it, and something clicks in her mind. They are neither fae runes nor alchemical symbols, but a combination of both. In one, an alchemical symbol for "Transformation" is paired with a ancient fae rune representing "Glamour" - for what is magic but transformation, and what is transformation but magic? And here, the symbol for fire, with a rune that represents passion... There, the sign for water and a rune for sorrow... Neither and both, making a new script that is unintelligible unless you have seen the pattern.
It unfolds, and she understands.