The same file shown on two screens rarely looks the same. Color is a chain of interpretations, and a mismatch at any link changes the result more than panel quality does.
A file describes color rather than containing it
Video stores numbers, not colors. Metadata tells the player which color primaries, transfer function and range those numbers refer to.
If that metadata is missing or wrong, the player guesses using a default. Two players with different defaults will then render the identical file differently and both believe they are correct.
This is the origin of the most common complaint in display reviewing, that footage looks flat on one device and oversaturated on another.
Full and limited range are the usual culprit
Broadcast conventions reserve part of the numeric range as headroom, while computer displays typically use the full range.
When a player assumes one and the display expects the other, blacks become gray and highlights clip. Nothing in the picture is broken; the two ends simply disagree about the scale.
The mismatch is easy to miss because it looks like a contrast preference rather than an error, which is why it survives into finished work so often.
High dynamic range adds another negotiation
Content graded for high dynamic range carries information about how bright it was mastered to be, which the display must map onto whatever brightness it can actually produce.
That mapping is proprietary and differs between manufacturers, so two capable displays legitimately produce different results from the same file without either being wrong.
Comparing displays therefore requires stating what content and what mapping were used, since the result is a property of the pair rather than of the screen alone.
Panel settings sit on top of everything
Consumer televisions ship in modes that boost saturation and sharpness, and many apply motion processing by default.
These adjustments happen after all the color interpretation described above, so a correctly handled file can still arrive looking nothing like the master.
Reviewers work in the most neutral available picture mode for this reason, and note that the mode itself is often renamed between model years.
What a reliable comparison requires
Meaningful comparison means fixing everything except the variable under test: the same file, the same player, the same output settings and the same picture mode.
Photographs of two screens side by side are not evidence, since the camera applies its own interpretation and the result depends on its exposure and white balance.
The defensible claim from a viewing test is about behavior, such as whether a display holds shadow detail, rather than about which one shows the true color of a file.