Why is the priest's photo significant, why are his teeth yellow, and is Eveline going to be a prostitute in Buenos Aires?

In Joyce's "Eveline," no, Eveline is not going to
Argentina to be a prostitute.  Why would you think that?  Is that what you think of when
you think of Argentina?  There is nothing whatsoever in the story about Eveline going
into prostitution.  She is a 19-year-old woman with a lousy life who meets a sailor and
wants to go away.

The importance of the photo is that the
priest pictured is one more person to add to the list of people who have left Ireland. 
The story is filled with people who leave Ireland, and that is what Eveline wants to
do. 

The photo is described as yellow because it's
deteriorated; it's old.  And of course this, by extension, suggests the state of Ireland
itself.