Hugs and Kisses for your Coal Man?
Today XOXOXO is not usually associated with holes in the sidewalk for pouring coal down into basements. While some philologists have traced the use of Xes back a few hundred years as signs of affection, the modern understanding of "hugs and kisses" may date back only 3 or 4 decades. So the meaning of XOXOXOXOXOXO may simply be a decorative device on this coal cover that has all the signs of being from the early 20th century
The central design -- a five pointed star surrounded by rings of studs (usually 7) and a circular badge near the edge -- was used by many small scale foundries in the New York City area. The outer ring was usually reserved for the foundry (or retailers) name and address, although maybe in this case the caster was known by his reputation alone.
Typical cole hole cover
This cover is near Grand Army Plaza in Brooklyn on Plaza Street West. A similar, but not identical, manhole was recently in Murray Hill at E 35th and 5th Ave. in Ephemeral New York