[Publius6961]

It’s just the property-interest in the flag itself that you find confusing?

Not in the slightest.
You are the one who introduced the red herring that 'it was not his flag' to desecrate.

[1rudeboy]

Let me try this in another way you might find easier to understand. You have the constitutional right to burn your American flag. You do not have the constitutional right to burn my American flag.