The first photo, of actress Goldie Hawn, represents something like delight? Joy? Excitement? But it seems fake, like Goldie isn't experiencing it but rather she's projecting it outwards, communicating it to the viewer.
In that sense, it's almost like it represents the idea of fun or excitement.
The photo of Billie Eilish, on the other hand, seems to capture her in a moment of genuine happiness and delight.
One clue is that when people are genuinely smiling, they get creases around their eyes. Goldie Hawn's eyes are round and creaseless; Billie Eilish's are crinkled.
There's also something about looking direct to camera and looking off—as if we as an audience know there is no real reason for Goldie Hawn to look at us with such exaggerated delight, but we believe Billie Eilish is delighted by whatever she sees out-of-frame (even if it's the image of herself with the heart filter on her head).