There is a lot about this photo of Sadie that I love. The tone is wonderful. I like the color of the worn bench that echoes the copper coloring of Sadie. When I take a shot of the pets I really like to see the whiskers -- here these above Sadie's eyes are an extra special touch. The overall color in the frame works -- the many shades of brown/tan/copper with bits of steel gray and blue are a pleasing combination. And the element that really brings all of this together and makes it work so well is the light -- the soft window light.
This photo is the cat sitting in front of the Christmas Tree. I did convert this to black and white -- although the color version is just as good to me. I like the metallic look of this one. The light in her eye is nice and the whiskers again here make it work well. There is just enough light hitting the front of the face, whiskers and chest.
Both of these photos were taken with the 50mm 1.4. That is by far my favorite lens. I have been using it a lot lately to really work the depth of field and to use available light. The wider aperture of this lens lets more light in so the shutter can work faster in low light situations.