There is this old request:
https://bugs.documentfoundation.org/show_bug.cgi?id=90864
GALLERY: image tooltips/names not translated
If it were to be implemented, localisation information would have to be somehow included inside the gallery packages. In other words, many unknowns and moving parts. Also pending the finishing of the migration to the new gallery package format.
I wanted to ask from the localisation community, do you consider it important to have these translatable?
Ilmari