Again quoting from the Golden Legend; "He also washed the feet of
the poor and gave alms to all." (Princeton 1993 edition, vol.2 p.65).
Washing the feet of the poor is a popular hagiographic topos signifying
humility, the obvious refererence to Christ's washing of the feet of his
disciples making it a clear depiction of the saint as "alter Christos".
Titulus top-right reads "S LAVRENTIVS"