How do you get your profile photo to appear in an email?

Hi,
I'm a bit confused as to the purpose of profile photos. I've come across emails (non-zoho emails) where the sender has a small photo id. With Gmail, this was easy but I've not noticed this take effect with Zoho email. Is there a setting I've missed or this feature is not with Zoho emails? as I've sent emails and noticed nothing was attached to the id (email sender).

Thanks for reading.