KRAKOW, Poland — A peace activist in the western Ukrainian city of Lviv rolled 109 baby strollers into a square last week to represent the children who had been killed in the war with Russia. Hours later, the image was available to millions on their phones.

A little girl sheltering in a basement in Kyiv sang a haunting rendition of “Let it Go,” from the movie “Frozen,” and the clip sped around the world. A cellist performed a somber Bach suite on a street in Kharkiv, with debris and the windowless facade of a damaged building serving as his backdrop, and thousands watched.

These heart-wrenching glimpses of life in Ukraine since the Russian invasion have become powerful ammunition in an information war playing out on social media. For some, the messaging has become a crucial battleground complementing the Ukrainian military’s performance on the physical front lines, as images and information ripple out on Instagram, Facebook, Telegram and TikTok.

“We are experiencing the war very viscerally through social media feeds,” said Emerson Brooking, a resident senior fellow at the Atlantic Council, a Washington-based international-affairs think tank. “The transformation of Ukraine into a nation at war is just stark. And so it has especially resonated with Western audiences.”