Wrong profile picture seen by other

The RFC standards for email do not support profile photos, hence they are not being sent with your email messages.

Some services allow for inter-account profile photo sharing - for example Gmail users can publicly share their profile photo with other Gmail users, but this won't be shared with iCloud or Ourlook. In other cases, like with Outlook for Business, profile photos of staff can be shared across the whole company.

In all other cases, it's the local contact list which is used to insert profile photos into the email app interface itself. This is likely what is happening in the case you have identified where a profile photo is attached to a contact which matches the email address which was sent from.

Your account picture is not sent with your emails. You have no control over what the recipient sees.

This is not an iCloud issue or an Apple issue, but a Gmail issue.

You could try asking in the Gmail Community.