Vocabulary: http://www.ivoa.net/rdf/datalink/core
Author: pdowler.cadc@gmail.com
Date: 2021-10-18

Term: thumbnail
Action: Addition
Label: Small Graphical Representation
Description: A very small preview suitable for displaying many at one time
Relationships: rdfs:subProperyOf(preview)
Used-in: https://ws.cadc-ccda.hia-iha.nrc-cnrc.gc.ca/caom2ops/datalink?ID=ivo://cadc.nrc.ca/BLAST?BLASTabell31122006-12-21/REDUCED_250_2009-03-06

Rationale: The term is used to specify that the link target is a small
preview suitable for displaying many such "thumbnails" at one time. The
primary use case is for a user interface to load or display these in a
table or as a popup, usually one per row but a grid of thumbnails might
be useful as well.

This is used in the CADC AdvancedSearch user interface as a popup when
users mouse over the preview links and allows the application to load
many of these at once. Example (BLAST + calibrated image query): 

https://www.cadc-ccda.hia-iha.nrc-cnrc.gc.ca/en/search/?Observation.collection=BLAST&Plane.calibrationLevel=2

Discussion:
  The on-list discussion of this VEP,
  http://mail.ivoa.net/pipermail/semantics/2021-December/002913.html,
  brought some clarification of the rationale, but did not uncover a
  serious need to sharpen the definition.