Just two things I thought might be useful to share:
"image size" parameter currently provides two options "medium" and "original", where "medium" in fact Flickr's "small" and may be too small for zoom in. Simple workaround is to add new option with any value besides "m","o","b" in the list of "size" parameter in the module's mod_JFlickr.xml file, like:
This will cause JFlickr.js to construct a request for Flickr's default image size which currently is "Medium500".
-----suggestion (to the author)
JFlickr requires jbLibrary plugin installed. Once installed two http request added to each site page (jquery-1.3.2.min.js and jquery.lazyload.js), which is performance wise is not so good if JFlickr the only client of jbLibrary.
It would be useful to resolve somehow this issue.