1st panel: The image of Death as a little or juvenile, sometimes winged boy who is holding a downwards turned torch was the way the ancient greeks pictured Thanatos, god of death and twin brother of Hypnos, god of sleep.
At least according to the theories of Gotthold Ephraim Lessing, a german scholar and writer from the 18th century. Whether he was right is still debated among art historians, but the theory itself is still extremely popular.
Be that as it may, the question of how the ancients pictured Death is a little more complex than that. The main problem is that they certainly didn't imagine Death the way we are used to see him, because our view is heavily influenced by christianity. In a way, our image of Death is still the one that came up in the middle / at the end of the 14th century, along with the Danse macabre (Dance of Death) and later on Ars moriendi and the story of The 3 Living and the 3 Dead.
Ancient mythology doesn't have the one and only (powerful) image of Death. The idea is sort of 'split up', on one side we have Thanatos, who IS in fact Death incarnate. Yet, his importance among the gods is nothing compared to Hades, god of the underworld.

2nd panel: In case the young lady does not look familiar to you: It's Death from the comic series "The Sandman" by Neil Gaiman (DC Vertigo Comics).
I actually liked the comic, it's only (my) Death who feels offended by being portrayed as this oh-so-lovely-goth-chick, but as you can see, he's not a big fan of any human depiction of his, other than maybe the Grim Reaper. Bit of a juvenile attitude, if you ask me.
Update 2022: As it happens, The Sandman is finally being transmutated from still into moving pictures. Writing this in May, the Netflix TV series is going to air soon, and I am REALLY excited of how they translated Death about 35 years from her first appearance!