Global sea level rise since 1898 has been 210mm or about 8.25 inches. That is very slightly more than one-fourth the width of one of the statue's eyes which are not visible in either photograph. And then, of course, there are the tides which range 5 feet at this location. Finding that I also came across this:
Tide measurements near the Statue of Liberty from 1855 to today show a 2.9mm rise in sea level every year. Tiny compared to the 5-foot range bet low & high tide, so you'd need photos (at the same point in the tidal cycle) to see a difference.
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So, that's complete bullshit in every way it could be.
How many times do you have to be told facts before they'll stick in your craw? That rock has been moved. See:
Plymouth Rock Location & History | Where Is Plymouth Rock? | Study.com.