Powershell ConvertFrom-Json with arrays adds extra spaces to an array value

When writing a powershell script with a ConvertFrom-Json, it seems that values in arrays are converted with additional spaces when casting them to a string. The following code shows this in a small code sample:

$object = @"
     { 
          "object":
          {            
            "prop1": "value",
            "array":[
               { "key": "value"},
               { "key2": "valuevalue"},
               { "key3": "valuevalue"},
               { "key4": "valuevalue"},
               { "key5": "valuevalue"}
            ]
          }
     } 
"@ | ConvertFrom-Json

$object.object.prop1
$object.object.array.key

$t = $object.object.prop1
$t2= $object.object.array.key
"""$t"""
"""$t2"""

Output:

value
value
"value"
"value    "

Where are the extra spaces coming from in the last value? When adding more value pairs to the array, more spaces are added.