Why is baby Jesus holding a bird?
In Renaissance era religious paintings, the small bird often shown in baby Jesus's hand is the European goldfinch. At that time, it was a popular pet for children because of its beautiful plumage, which included red feathers around its beak. According to James Hall in Dictionary of Subjects and Symbols in Art, “The reason for its association with the Christ Child was the legend that it acquired its red spot at the moment when it flew down over the head of Christ on the road to Calvary and, as it drew a thorn from his brow, was splashed with a drop of the Savior’s blood.” The goldfinch can symbolize the soul, resurrection, sacrifice and death... Following the plagues of the 14th century, it also took on a another meaning as a symbol of healing and redemption.
Apparently, in 1946, an ornithologist named Herbert Friedmann made a scholarly study of this phenomenon in which he traced no fewer than 486 devotional pictures containing the goldfinch!
Why is this baby so buff?
He does indeed seem to be sporting a bit of a six-pack! Artists during the Italian Renaissance had an interesting challenge in depicting this Christ Child because, by his very nature, he is human and divine at the same time.
So, they wanted to stress his natural baby-like behavior (being held by his earthly mother, having a chubby face), but they also wanted to give him respect and demonstrate his significance. For the latter reasons, he often looks more "adult-like" than we might expect, in certain ways. He is sometimes draped in a sheer cloth, which shows us his human baby body yet also gives him modesty and dignity.
Yay for Jesus!
Who are the four figures around the Madonna and baby Jesus?
Clockwise from the lower left we see: John the Baptist identified by his bare feet and cross-shaped staff; Saint Zenobius, patron saint of Florence, dressed as a bishop; Reparata, a martyr and another patron saint of Florence characterized by her short hair; and John the Evangelist identified by his book.
What is the sheer fabric around the baby Jesus?
It was a compromise between portraying the baby Jesus as a child, often depicted naked in Renaissance art, but also affording him respect as the savior. This sheer drapery provided at least a modicum of modesty.
Why does it look like the Virgin Mary is wearing black?
That is an interesting observation, her mantle was actually a rich blue that has darkened over time. A blue mantle became the signature, identifying garment for the Virgin during the Medieval period. The symbolism of the color was that of purity and wealth. The traditional pigment was called ultramarine and derived from lapis lazuli, a brilliant, imported, precious stone that was only mined in Afghanistan.
Why do so many babies in historical paintings look so strange?
There is in fact a reason! One of the artistic innovations during the Renaissance in Europe was to sketch everything from life in order to paint it. Artists who didn't do that, had to recreate babies, for example, from memory.
Even though it sounds like a simple task, these paintings prove that without a reference in front of you, it's nearly impossible to get all the details right.
Another factor, in some paintings, is the way that artists attempt to rectify Jesus's nature as both divine and a human infant. This explains why you might see some representations of the Christ child with very adult looking muscles.
Do the gold designs have a certain meaning in the Nardo di Cione?
The designs are largely decorative. The inclusion of gold here is a holdover from a Byzantine style of religious painting where it is meant to suggest the otherworldly, heavenly space that the Virgin and Child occupy. The patterning that Nardo di Cione includes is a more elaborate way to depict the halos and backdrop of the portrait.
Why does the human figure have low saturation?
What you might be reading as "low saturation" may be related to the early Renaissance practice of trying to portray a more realistic human body, which meant more shading and thus more grey tones included in the flesh.
A relative paleness, however, was typical of depictions of people in Italian Renaissance art.
Why is her facial expression emotionless?
If you look at all of the faces in this painting, none of them show a lot of emotion. A painting like this was thought of as being made for God and for eternity. A resting, or relaxed face fits the function.
You may notice in depictions of the crucifixion, for example, that Mary is shown clearly grieving, but depicting someone smiling in formal painting didn’t become acceptable until the 18th century.
What does the flag in the background represent?
It's known as the flag of Christ Triumphant, because Christ is often seen carrying it in scenes of his resurrection, having triumphed over death.
Here it is carried by Reparata, a patron saint of Florence and martyr. Martyrs, in Christianity, are considered to have also triumphed over death. Additionally, it can be seen as foreshadowing the resurrection of the Christ child depicted in this painting.