Clint is seen drinking out of a coffee mug that says "Thanos was right." That same phrase appeared as graffiti on a urinal in Never Meet Your Heroes (2021).
On the morning after the "ugly sweater party" when Clint tells Kate to go see the LARPers, she's wearing a white shirt commemorating the first living being to orbit Earth (and die there), the dog Laika on the Soviet spacecraft Sputnik 2. On her shirt, there's a stylized picture of a dog in a spacecraft. The inscription is "Laika" in Cyrillic script.