Dude you actually have to post the pictures for us to answer the questions...
Answer:
It uses light and oddities like a floating head to show that it is not a living person, the head in question looks close to representations of religious figure Jesus. So, we can deduce that the "Apparition" symbolizes something different than just a head with no body.
Explanation:
It is called "Concerto grosso"
Answer:
Oblique drawing is a projective drawing in which the frontal lines or face are given in true proportions and relations.
Explanation:
1:An oblique sketch puts more focus on the face or front of an object .
2:An oblique sketches are usually drawn using a 45 degree angle to render the 3rd dimension
