transitional period from Steth to ETH. Basically a "receipt". Correct?
Yes, technically it's your receipt in the withdrawal queue (to make sure order of withdrawals preserved). Note the NFT itself is what is used to claim the ETH being unstaked, so do not lose it, or trade it away (unless you do so intentionally, in which case you should probably ask at leat as much as the ETH being unstaked is worth). If you send the NFT to another address, then the claim also needs to happen with the other address.
Perfect, very clear
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