My guess is that Mare Liberty here was built by the Earth Ponies as a reminder to the Unicorns and Pegasi that they’re no longer serfs like they were in the bad old pre-Equestria days, but free and equal ponies now. Which means it’s kind of a “Take That” to Celestia and the other Princesses.
Actually based on what Celestia and Luna said about their roles as princesses in The Journal of the Two Sisters, Equestria is more akin to the British Commonwealth or more specifically the Commonwealth Realm (the collection of countries in the British Commonwealth that still recognize the ruling British monarch as their head of state) in that it is actually a collection of individual territories, each with a certain degree of autonomy that recognizes the princesses as the heads of the Equestrian Commonwealth or whatever its official title is. Manehattan probably prides itself on being the largest and most democratic territory of the Equestrian Commonwealth and most likely had that statue built to represent that, but that’s mostly speculation on my part.
Which means ponyverse Statue of Liberty is like thousands of years old wow that’s trippy.
@Background Pony #D733
Pre-Equestria didn’t have Celestia and Luna as leaders so if anything it would be a metaphorical middle finger to the other races.
In any case, I would make Mare Liberty a declaration of liberty to other non-Equestrians coming in (for tourism or immigration) since it does sit at the edge of the ports would go.