This feature allows you to vote on behalf of your customer. It is helpful for you:
Open the post you want to add the vote to. Then click "add voter" on the right side.
Add the vote of your customer by entering their email or name. Their account will automatically show up.
Select the account and vote.
If the account is not showing up, the person has no account or is not invited yet. In that case, tick the checkbox for a new account.
The user will be created, they get an invite and their vote is added to the post. If you don't want to send the invite, you can tick the box "Invite without sending an email".
The vote is completed and is added to your list of "voters & followers".