when in game mode 3 you cannot see what record (or not) is inside jukeboxes.
How to reproduce:
1. place a jukebox and then a record inside (or no record)
2. go into gamemode 3
3. right click or left click jukebox
MC-47258
game mode 3 jukebox
Resolved
Works As Intended
0
So you can't in any other gamemode.
The Jukebox is no container and thus has no inventory.