In my opinion, that is bull**** expectations from admissions. The actual doctor work (eg professional obligations to adhere to standards of care and practice) are the same regardless of modality of practice. The only differences are ownership and delegation of administrative duties and business model.
Commercial, Private practice owned by optom, private practice owned by oph, VA hospital/HMO/public health center, academia, military, home-visit.
I've never worked in admissions, but I can't imagine SHADOWING DIFFERENT MODALITIES would hold any influence over something more critical like ECs, gpa, oat; namely because it doesn't sound helpful, and the fact you will there is a slam chance that you won't shadow anyone that isn't a private practice doctor since others cannot give authorization to have some non-organization entity observe an exam per organizational compliance standards.
I wouldn't worry about actually shadowing different modalities, rather I'd at least be knowledgeable about what exists.