  We compare and contrast the two approaches of holography in asymptotically
flat spacetimes, viz. the co-dimension two Celestial approach based on the
Mellin transformation and the co-dimension one Carrollian approach based on the
modified Mellin and elucidate how some of the problems of the Celestial
approach can be rectified by the Carrollian one. Considering flat holography as
a limit from AdS/CFT makes a co-dimension one dual more plausible, and our
previous construction of Carrollian correlations from AdS Witten diagrams is
testimony to this. In this paper, we show how to generalize our earlier
analysis for operators with spin. We work out a large number of explicit
non-trivial examples (twelve) and show matching between the limit of AdS$_4$
Witten diagrams and 3d boundary symmetry considerations, thus making the case
for the Carrollian dual even stronger.
