Anyways after looking at Childe's vision i've concluded that the Cryo statues of the seven are holding a sphere with spikes around it
Cause i've been thinking some more, and I guess vision shape is probably tied to the statues of the seven, because the vision and vision frame resemble what the statues are holding
So maybe they're given out through the statues...?
hmmm, in general, i think you're onto something, but i still would like to respectfully point out my reasons as to why i think you might be overthinking some things.
to clarify, i think the visions probably do tie into the statues, but you might be overthinking the significance of the statues themselves.
let's look at an example:
if we look at diluc's vision (a standard mondstadt vision), it's a glass ball in a frame, which is golden and has little flares on the bottom.
now if we look at the mondstadt statue of seven:
(source; i believe it's the thumbnail)
it's true that if you look at him from a front perspective, it sure seems that venti is holding a ball (vision) and his wings make the little flares.
venti is not HOLDING a ball with flares. it's just what happens when you look at him from the front and neglect the general shape of the statue.
okay, so you might say that i'm cheating and pointing out a flaw in your wording HAHA which i don't deny! it's true that that's what i did, and it's also true that if you look at zhongli and baal's statues of seven (and their respective visions), the shapes do generally match up with their statues.
but in general, each nation has its own geometric correspondence. for mondstadt, it was a ball (and angel wings symbolizing freedom). for liyue, it was a cube (and hexagonal prisms, if you go to guyun, symbolizing stability). for inazuma, it seems to be connected circles, which may symbolize rebirth or cycles, or a sort of eternity.
hence, i think that the statues' aesthetics probably are not as important as you think; instead, i think they're just like that because of set nation characteristics.
that said, we were talking about tartaglia and snezhnaya.
first off, tartaglia's vision is a sideways fatui agent badge (fatui pyro agent badge for comparison), probably because he is a fatui harbinger. then again, since we know fatui pyro agents have, well, pyro powers, and their badge looks nothing like a vision (nor can we see any visions on their bodies), we can assume that their agent badge is actually a delusion which allows them to use pyro powers.
which then means that it's quite likely that tartaglia's vision frame (and the pyro agents' frames) do, indeed, represent the snezhnaya vision frames.
sorry for that longass intro, i just wanted to list all of our assumptions and figure out whether or not they're valid. my thought process was 'well he's a harbinger, maybe it was smth the tsaritsa gave him since, you know, pyro agents also have these frames' but we know that tartaglia's vision is real so it, at least, should be representative of what real visions look like (delusions aside lmao).
anyway, now that we've established that tartaglia's vision frame is probably NOT a governmental accessory, let's break it down even more.
i found this picture of tartaglia's vision (which is quite detailed), and you say it means the statues might be holding a sphere with spikes, right? i have refuted that above, so i will go the opposite route: i do NOT think that the snezhnaya statue of seven will be holding a sphere with spikes.
but i DO think that spikes will have to do with the general aesthetic. and why is that?
this was the first thing to flash through my head when i thought about the spikes. this is a picture of pucinella, the fifth harbinger, as shown in the snezhnaya section of the teyvat timeline trailer.
so while it could be very fair and tsaritsa's statues of seven could be holding a ball with spikes, i'd bet more on the general aesthetic of the nation having to do more with spikes of ice, hence the statues having a similar aesthetic as well.
that was a super long post mostly because i am tired and couldn't organize my thoughts properly HAHAHA pls do keep in mind that my theories are only my own, and yours are equally as valid as long as mihoyo hasn't confirmed anything!