I noticed this van parked along North Capitol Street NE near New York Avenue NW this past weekend.
So it appears that there is a partnership of sorts between So Others Might Eat (S.O.M.E.), which has a feeding facility on the unit block of O Street NW), and Walmart, which will be opening a retail store soon at 77 H Street NW, located at the intersection of 1st, H and New Jersey Avenue NW.

See this tweet and subsequent tweet response to the post above:
Jonathan Rogers @JRogers202 1h
Perhaps @SOME_DC can elaborate on partnership with Walmart https://batesareacivicassociation.org/2013/09/16/van-seen-near-north-capitol-and-new-york-ave-ne/ … via @dcbaca
So Others Might Eat@SOME_DC 42m
@jrogers202 We purchased a van with a gift from Walmart. It allows us to deliver food to homebound and isolated DC seniors
SOME says “We purchased a van with a gift from Walmart. It allows us to deliver food to homebound and isolated DC seniors” https://twitter.com/SOME_DC/status/379709382378156033
that van has been around for a little while now. It usually parks on P st NE across from Yums