Giotto's painting uses neoplatonic thought in that it is the story of the last judgment, this story is the exact definition of neoplatonism, people await to be judged by Jesus to see whether they will go to hell or heaven, they await judgment in purgatory. Both paintings have a depiction of hell and heaven, both depict Jesus and the greek god of the underworld minos. Both paintings are humanistic in that they are both from the time of the Renaissance, a time where creating art was prevalent and growing, the skills of a painter was evolving from one painter to the next, Michelangelo painting in comparison to Giotto's is a perfect example of humanistic qualities, the Renaissance was all about the improvement of art, Giotto's techniques are astounding for it's time, then came Michelangelo's that references Giotto's but Michelangelo's grasp on art is much more advanced because he has 200 years more experience of art to study than Giotto ever did, a perfect example of humanism. In comparison of the iconography the people look much more realistic than Giotto's and although Giotto's is full of illusions and iconography, Michelangelo's has a lot more in comparison, also King Minos of the Underworld is much more detailed and he isn't eating anyone in this painting instead he has donkey ears and is being coiled but a snake and one part of the snake's mouth is on his crotch while in Giotto's Minos is eating people and they're coming out of his bowels. Both paintings both have apostles and saints to the left and right of Jesus but in Michelangelo's they're all nearly naked but in Giotto's they are more clothed. Both paitings share a similar style in that they're both horrifying in a way, like it was their intent to have the painting to scare the viewer, in a way, possibly to not sin.
In my opinion Michelangelo's "Last Judgment" is the correction of Giotto's painting. In Michelangelo's painting, the figures are in very complex postures, and many different characters and variety of facial expressions. Also, in Michelangelo's painting the characters seems more realistic and alive because each of them gives different body posture , action and facial expression. For example, However, the similarity in iconography of both paintings are the placements of the figures such as God is placed in the center in both paintings.
Well both paintings are neoplatonic in that they attempt to express a relationship with the God and the after life. Both do this using similar figures and positioning of those figures such as Jesus in the middle of the painting and Hell and Heaven to the left and right of him. Where they differ is how Michelangelo's painting is more fluid and detailed. If you look at each scene, it seems to me more alive or graphic than Giotto's. The detail of the bodies of each figure are also more detailed. I think both artists try to convey their humanistic intent through the existence of the painting itself. It is a reminder that to make it into heaven, one must be a good human being first. A. Martinez