I have lots of collections with "dynamic" array elements. These typically are shown like that:

• items [20 elements]
• 0 { 3 fields }
• 1 { 3 fields }
• ...
• 19 { 3 fields }

In my opinion, the field number is usually not very helpful. It would boost productivity significantly if I would see the data directly, i.e.

• items [20 elements]
• 0 { id: 112, name: dummy 1, value: -0.3 }
• 1 { id: 709, name: Long dummy name, whi...
• ...
• 19 { id: 583, name: dummy x, value: 4 }

Overlong data can be cut off at the column width. To avoid unneeded data retrieval, only the direct descendants can be shown.

In principle this can also be applied to the top-level documents. Instead of simply displaying the field count, the _id would be visible in the 'value' column and no exception needs to be made in the 'key' column (which would be more appropriate IMHO).