They appear to be of different construction and by different hands. The bottom one looks drawn as well - unnatural.
Yeah the bottom one doesn’t look right I agree , it’s more the above that I can’t quite figure
I don't know this signature but both appear to be simulations.
The signed photo River one looks real to me. The bottom looks forged, no fluidity. There are wonky lines in it, like the person signing has taken their time. The fluidity gives it away. I'm skeptical on that one. I'd suggest contact Tom Kramer from Golden Age autographs.
Also, I have a Jeff Buckley autograph too, show me it and I will be able to tell you if it's real. I've had a lot of experience with his writing, dedications and signature.