Get image url from model good practice?

I am not very convinced about this method because I must do a foreach in models. And let me tell you why:

in Products model I may have:

select_by_id
select_by_slug
select_by_category_id_by_limit
select_by_category_slug_by_limit
entries_by_limit

And think that I must make a foreach inside all this models. A lot of duplicate foreach ....