Good comments, thanks.
Shot wise, the second was rather difficult. The web is roughly 5' across and the wind would blow the spider in and out several inches. At times I was worried the wind would blow the spider onto my lens as it was quite close (6-7" away with no wind). With the motion focusing on the head was challenging and took many exposures before finally getting something even close. I also tried setting the focal plane in a variety of positions considering the wind, and big surprise, only those with the head area in rough focus felt right.
For me, this was a look at light in general and how strong backlighting can impact an image in specific. The first shot is in a soft shaded morning light, and the other way more harsh direct afternoon sun. The softer light is very pleasing to me, but for drama, I do like the highlighting of the web and leg hairs of the backlit shot, although being in a different plane from the head of the spider the legs and their hairs are not in focus.
I asked the spider to move to the other side of its web, so I could shoot it top down instead of belly up, but it wanted unreasonable modeling fees so I had to shoot it as it lay. Shooting the belly of the spider the underside is not as recognizable and eyes are not visible.
Lightwise, as jroovers points out, what the backlit shot is missing is a pop of front flash to properly illuminate the underside of the spider. I'm getting why Jesse uses his a lot in his bug shots.