Face with tears of joy is the world's most used emoji, typically signaling something is hilariously funny or absurd in a lighthearted, often playful way.
Face screaming in fear stands for shock, fear, or exaggerated panic, usually used when something is surprising, dramatic, or meant to be a big, dramatic reaction.
Both convey strong, immediate reactions to something surprising or funny.
Face with tears of joy centers on laughter and humor, while face screaming in fear centers on shock or alarm.