Currently, if you try to look at say a mill, or a silo, it can't pull the building information up. Is it possible to add this to a later release?

Sure. What kind of information would you want displayed?

I mean, in general, I think it should display processing information if it's that type of building, or what it holds for a silo.

I'm wondering what information it should display for a shed, or a barn, or coop or slime hutch though..

For a coop (for example), you could show what animals are stored in that coop (along with their names, pet status, and mood) and how many are inside (as opposed to outside). You can also show how many eggs are waiting to be picked up, how much hay is on the feeding bench (if you don't have the autofeeder), and the status of the incubator.

Done in develop for the upcoming Lookup Anything 1.21:

These fields are implemented:

• general:
  • translated name + description from blueprint
  • 'under construction' completion date
  • upgrade completion date
• barn/coop:
  • number of animals housed
  • total capacity
  • feed trough status
  • upgrade levels
• cabin:
  • owner (link to player info)
  • upgrade levels
• Junimo hut:
  • whether harvesting is enabled
  • whether items are ready to collect
• mill:
  • items ready / being processed
• silo:
  • stored hay
  • total hay
• slime hutch:
  • number of slimes houses + total capacity
  • water trough status
• stable:
  • owner (link to player info)
  • horse name + location

The egg/slime incubator status might be implemented in a future version.