Oooh, this is a tough one. I believe the image tags only work with links pointing to actual image files (typically JPG files) but they don't work well with links to directories or folders (which is what I suspect is going on here).
I used to see this with Imgur. There are multiple mobile apps for Imgur and one of the ones I used only provided the link to a folder as opposed to a link to an actual image file. In my case, I simply used the appropriate Imgur app that provided links to the image file.
I am not familiar with with using Flickr but a quick Google search yielded this link to the Flickr Help Forum
. It's a bit dated but you should find your answer in here. Good luck with this.
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