Define which property needs verification
A filename can contain resolution, codec or edition words without proving those properties. Begin by stating the actual question, such as whether two copies have different dimensions or whether a video uses the expected compression format. Keep the original files unchanged.
Use a file you are permitted to inspect and open it in the intended QuickTime Player installation. Record which copy is active when several have similar names. A technically valid report for the wrong file can produce a misleading comparison even when every number was read correctly.
Open the documented inspector
Apple documents Window, Show Movie Inspector and Command-I. The inspector displays source information such as format, dimensions, frame rate and other media properties where available. Use the actual fields shown for the opened file rather than assuming an old screenshot lists every current item.
Keep units attached to the values and distinguish a missing field from a measured zero. An application not showing a property is an evidence limit, not proof that the underlying feature is absent. If another utility is needed, record its identity and compare the same file.
Compare two copies through a small record
Inspect the first copy and note the specific fields relevant to the task. Open the second copy and repeat without changing playback or output settings. A concise private table with filename, dimensions, format and observed playback is easier to assess than an unlabelled collection of screenshots.
For an original example, one copy may use the same dimensions but a different codec or data rate. Those differences should not be collapsed into a single quality label. Actual source detail and perceived playback quality need more evidence than one numerical field.
Questions answered
Can the inspector prove what the television physically displayed?
It reports media information for the opened source. The external display path requires its own observation.
Why record the filename with the values?
It prevents results from similarly named copies being assigned to the wrong source.
Sources & further reading
Official references for the subjects discussed. Service terms and device software can change.