Missmolly, are you sure that the link is to the image only? If it were so only an image would be shown without any text and graphics. It would not say Flickr.
I agree a seller should take their own photos and show what is actually being sold. But if they do not have a photo in this case of the flower I think it is legit to put a link to some webpage that may show that, as long as it is stated that is an external website. Some vendor used links to the IOSPE photos.
If the photo would be embedded in the listing i would see that an infringement of copyright and also stealing bandwidth from the website where the photo is hosted, Regarding the NY Times example it is not what I meant. Sometimes news sites pick up stories reported by other sources and put a link to other websites that broke the story.
if the link would be like this that would be unethical.
but if the link is like this it seems to me legit and ethical
IOSPE PHOTOS
I am going to check the vendor
here they put a link to IOSPE
Schomburgkia splendida Species Orchid Plant.
here a link to bela vista orchids
Laelia grandis vinicolor Species.
the links are to webpages, not to individual images. To me it seems a legit use for reference. The links are to public pages. It seems ethical to me.
Someone could theoretically decide to buy from Bela Vista Orchids.
here there is no external links
at all, the bloom photo may be owned by the vendor
Ophidion pleurothallopsis Species Orchid Plant.