Or it's a different document. A registry entry rather than a copy of the registration. Note that they Taitz document refers to a Birth Register, as the original "source" document. Since it does have the signature of the "informant", apparently a district official, it is likely a copy of the original, rather than an "abstract" like the Taitz document or for that matter, the "Obama" COLB.
it appears to also be from 1964 see the number on the right side margin GPK 209-20mm 1/64
GPK appears on modern Kenya documents