Owners of this NFT will see that you made an offer for this NFT. If they accept, you will pay the agreed upon amount, and ownership of the NFT will be transferred to you.
When you place an offer, an authorization for the amount you offered will be placed on your card. If the offer is accepted, the authorization is converted to a charge. If you cancel the offer, if the offer is declined, or if the offer expires (which will happen after 7 days), the authorization will be reversed and the charge will disappear from your card instantly.