Nothing / unspecified
Critical Role often plays it a little fast and loose with the exact rules of spells, and they quite frequently forget to account for material component costs of spells - especially new spells they have just learned. Matt seems loathe to retroactively edit anything that hasn't just immediately happened, so they tend to get away with it unless it's something that's resolved by a simple bookkeeping adjustment (i.e. "you actually used up all your diamond dust casting greater restorations last session").
The most likely explanation is that Jester scried once or twice without using an expensive focus because they forgot she needed one, and then the established precedent is that she doesn't need a focus, and to maintain consistency that's simply how it is now because her early scrying attempts were pretty crucial for advancing the plot. She has never been described as using a proper scrying focus for the spell nor acquiring one, so if she has picked one up it happened off-camera.
Alternatively, she does lay out a bunch of little accoutrements whenever she's performing the ritual, including Traveller paraphernalia she made herself and various interesting things she's found in the world. We've never been given a cost for these, but it's possible Matt decided that they collectively constitute 1,000gp worth of scrying focus.
As a final note, the way that scrying is used in Critical Role is significantly less powerful than the RAW actually allows; in the show Matt only allows a clear view of the specific target of the spell, and makes other creatures and the environment very indistinct and unclear unless they are very close to the target, whereas the actual effect of the spell is just that you can see and hear as if you were in the scrying sensor's location.