The "os" is very different as well.
Also note the big "N" always has that little thin line connecting to the "a" in all of them but the last.
Big N
Little n
Little y
The "os"
Perhaps multiple copies of the Pelosi letter were distributed with slightly different signatures to catch a leaker??
Would be nice to include some context. Are those people for or against Maduro? Guessing against since they're all starving but would be nice to know for sure.