Let us leave the retainer's inventory window open while checking other windows. The majority of my retainer's inventory is crafting ingredients, and I'd like to be able to reference my crafting log while choosing which items to pick up. The usual pattern is currently:
  1. open crafting log
  2. check ingredients for the first recipe I'm interested in, finding I'll need ingredients A, B, and C (among others).
  3. close the crafting log
  4. use bell to summon my retainer
  5. acknowlege her greeting
  6. select that I want to transfer items
  7. pick up ingredients A, B, and C
  8. close the retainer window
  9. acknowlege her farewell
  10. open crafting log
  11. check for the next ingredients I'll need, finding I'll need ingredients D, E, and F.
  12. close the crafting log
  13. use bell to summon my retainer
  14. acknowlege her greeting
  15. select that I want to transfer items
  16. pick up ingredients D, E, and F
  17. close the retainer window
  18. acknowlege her farewell
  19. open crafting log
  20. check for the next ingredients I'll need, finding I'll need ingredients G, H, and I.
  21. close the crafting log
  22. use bell to summon my retainer
  23. acknowlege her greeting
  24. select that I want to transfer items
  25. pick up ingredients G, H, and I
  26. close the retainer window
  27. acknowlege her farewell
  28. open crafting log
  29. check for the next ingredients I'll need, finding I'll need ingredients J, K, and L.
  30. close the crafting log
  31. use bell to summon my retainer
  32. acknowlege her greeting
  33. select that I want to transfer items
  34. pick up ingredients J, K, and L
  35. close the retainer window
  36. acknowlege her farewell
  37. get fed up with all this going back and forth and decide to just get started
  38. begin crafting
  39. get stuck because I didn't pick up the rest of the ingredients I needed
I'm not asking to be able to craft directly with items in my retainer's inventory (though I know others have asked for that), but please let us see what it is we need to pick up while we're also on the window to pick it up from. Don't require that we have to dismiss our retainer just to look at other windows.

The crafting log is the most common and obvious example, but it could also apply to checking our quest journal to see whether we already have items we need for crafting/gathering leves, or checking the "timers" window to see what items have GC supply missions. I can even envision wanting to check the character window to compare our current gear to some that our retainer is holding. Basically, just allow our entire menu of UI windows to coexist with the retainer's inventory window.