Difference Between Obverse "Millitary Bust" And "Constantinople"

Constantinople is the mint, "military bust" is a description of Marcian's portrait. Those are in no way contradictory. In fact, at first glance both of those look applicable to both coins - but there's only so much space for text on the slab, and I guess the graders chose differently what to include in those two cases.

Unfortunately there's not enough attribution in the description to tell for sure whether those two coins are, in fact, the same type. (And the slab has no attribution at all - a strange decision by NGC.) They look like the same type to me, but for Roman coins sometimes very minor differences are important in attribution.