In this case I don't think It is anything to do with whether the person is living in an institution or not. Family Search has affiliates such as Find my past who I thought was the affilate for the census ( I certainly think it seems odd to call it an institution.)
The first page of the enumeration return in this case is a normal ie non institutional one.Its for part of Hoxton Old Town; enumeration district 3, the schedule on the first page of the enumerators' returns always lists in detail the streets and parts of streets covered.
The reference for Nathaniel's entry is.
HO107; Piece: 708; Book: 1; Civil Parish: St Leonard Shoreditch; County: Middlesex; Enumeration District: 3; Folio: 44; Page: 23;
The workhouse was in Hoxton New Town and has its own return
HO107; Piece: 707; Book: 9; Civil Parish: St Leonard Shoreditch; County: Middlesex; Enumeration District: St Lukes Workhouse; Folio: 16; .
Here is a record on FS for an inmate in that workhouse
England and Wales Census, 1841," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:MQVV-9Q9
: 13 December 2017), George Abraham, St Leonard Shoreditch, Middlesex, England; from "1841 England, Scotland and Wales census," database and images, findmypast (http://www.findmypast.com
: n.d.); citing PRO HO 107, The National Archives, Kew, Surrey.
The record includes the info that it is an institution ,and at the bottom the same note about FSearch's affiliate.