Panorama combines pan- with Greek hórāma. Together, the pieces suggest an all-encompassing view.
This is a later formation from Greek material, not an ancient Greek word panorama.
Sources
- Merriam-Webster: panorama
Word History identifies the second component and its seeing sense.
- Merriam-Webster: pan-
Combining-form Word History supplies all or every.
- Online Etymology Dictionary: pan-
Also built on *pan-* "all": panacea, pandemic, pandemonium