I do think you have a point, Rosemaryr. There has been a lot of debate concerning the "non-commercial use only" here lately. My interpretation is the one that appears widely accepted as the intention of the "non-commercial use only" indicator for free stuff. However, from legal perspective, I find it highly unlikely that anyone can forbid someone to include an item in a picture that is rendered for commercial reasons. I see this more as respecting the wish of the artist that generously offered the product for free. It's always safe (and polite as well) to ask first.