I think the description "External Links" is ambiguous, and could be improved.
In the upcoming Pano2VR 6.1beta, the Street View panel has a new item "External Links". I believe this is for adding links to other Street View tours that are "external" to the current tour. It would be better if this was named "Links to other panoramas", as "External links" suggests links that are completely external to Street View, which I don't think is the case.
It would also be useful if, when I click the "External links" + symbol, the dialog that pops up, provides a sentence explaining what to do next. At the moment, there is only a label "External Photo ID". I would add a sentence saying something like: (1) Click the Street View Browser (2) Optionally double click a tour to view its panoramas (3) Right-click a panorama and select "Add link to Other Panorama" (4) If necessary, repeat in the opposite direction.