Observation, not practice
Both routes are strictly observational. Observers and fellows do not come into physical contact with patients, do not examine or treat them, and do not perform or assist in procedures, regardless of their qualifications at home. This is a governance and patient-consent requirement of the host hospital.
What you do is follow the complete clinical process — pre-operative assessment, the operating theatre, post-operative care, ward rounds and multidisciplinary discussion — alongside the department's team, in a high-volume setting.
The certificate you receive documents attendance. It does not by itself confer clinical competence, a specialist qualification or the right to practise in any jurisdiction.