Separate the shallot rings and place them in a small bowl or jar.
Combine the red wine vinegar, sugar, salt, and warm water in a measuring cup. Stir until dissolved.
Pour the brine over the shallots. Let sit for at least 20 minutes until bright pink.
Add room-temperature cream cheese to a mixing bowl.
Whip on medium-high for 2–3 minutes until light and fluffy.
Add chopped chives, lemon zest, salt, and pepper.
Whip again for 30 seconds until incorporated.
Transfer to a piping bag and refrigerate for 20 minutes.
Arrange crackers on a serving board.
Pipe whipped cream cheese onto each cracker.
Drape smoked salmon over the cream cheese.
Top with pickled shallot rings, dill, and capers.
Finish with flaky sea salt.
