Symbolism counts for a lot in foreign policy. Adversarial leaders are photographed smiling and shaking hands to show thawing relations. They grimace to show public displeasure. Nonthreatening and soft symbolism makes a point about state relations without allowing for dangerous misinterpretation or miscalculation between nations.
Harder, more aggressive symbolic acts get a lot of immediate attention. In the worst case, they can really confuse matters or welcome unintended consequences. To make a tough point, adversarial nations will sail naval subs into other countries’ territorial waters (Russia), fly new stealth fighter jets during a state visit (China), or blow up nuclear weapons as warning shots (North Korea). This harder symbolism shows off increased military capacities, warns real and potential adversaries, and threatens everyone that these countries’ leaders are serious, if not downright unhinged.