The first shot is P mode, no flash, nice diffused light from behind. It's a little dark, but not bad. I popped the flash, full power but I underexposed the shot -.7 stops. It's washed out, just too bright for a great composition.
There's also annoying reflection from the flash off the window on the right. Flash diffusion may help us out. Since I was using the pop-up flash, and I couldn't find any old film cans, I resorted to a translucent caontainer lid. I think it worked great.
A soup container lid from the Chinese restaurant saved the dahlia photo from ruin.