Something which is similar to aliases is the "trail" concept I use in the report plugin. (Also my "pmap" plugin, but that's only in my "experimental" branch on github). One can define a "trail" by making a report with the "doscan" option (I should probably change the name of that) and then that page has a "trail" which matches the pagespec in that report. Then one can reference that page as a "trail" without having to reuse that pagespec. (It's also very useful in speeding up the processing, because the matching pages have been remembered, and one doesn't have to search for them again).

So, for example, one could make a page "all_images" and have a report (or pmap, which is simpler) like so:

[[!pmap  pages="*.png or *.jpg or *.jpeg or *.gif or *.ico"]]

And then later, somewhere else

[[!report  template="images.tmpl" trail="all_images" pages="album/*"]]

and that would show all the images under "album".