There are quite a few elements that contribute to the physical portion of an image.
A few are color, composition, lighting, and character emotion. The use of color appears to be carefully planned due to what some of those colors represent, which I will explain later on. In this painting, the artist used a vivid color palette, and also a very dark one, representing the despair of the situation. The green of Thetis's cloth harshly clashes with Jupiter's red toga. Perhaps the artist was trying to show further contrast between the characters to depict their differences.
The composition of this piece is very organized and even. Jupiter's broad body nearly takes up the entire canvas. I believe his stature in the painting shows the weight of his importance. It is his decision at this point whether or not the son of Thetis lives or dies. She seems small and insignificant in comparison. The painting is also proportioned well with Thetis and the eagle on either side of Jupiter, and his stance is mirrored on each side of the
painting.
The lighting in this photo is varied. There are darker aspects, like Jupiter's face, and the shadows on the clouds, and there are lighter aspects as well, such as the body of Thesis and Apollo playing his lyre in the upper left corner. Like many of the figures in this artists paintings I have seen, Jupiter and Thetis are heavily outlined. The shadows behind Jupiter's arms don't make a whole lot of sense since though because the sky is the background, so there is nothing for a shadow to fall on.
The most important emotion that is portrayed is the emotion of the pleading mother, Thetis. She makes a desperate attempt to save her son, making erotic gestures to try and get her way. She looks up at the unyielding god with the pleading passion of a beggar's eyes. Her lips are tight with the anticipation of his decision, almost as if she's ready to pour thanks from her lips if he grants her son safety. Her body is draped over him like she is unwilling to leave until she has the answer she desires. However, Jupiter sits quite confidently, completely unmoved by her presence. He stares ahead as if he barely notices her touch and her half naked body fawning on him.