Why does powershell ConvertFrom-Json not work when converting json array and streaming output to ForEach-Object

Question

This JSON array converted to powershell object seems to be somehow get handled as single string when streamed to ForEach-Object.

"[1, 2, 3]" | ConvertFrom-Json | ForEach-Object {Write-Host "Number: $_"}

Prints:

Number: 1 2 3

Expecting:

Number: 1
Number: 2
Number: 3

Although: "[1, 2, 3]" | ConvertFrom-Json

prints:

1
2
3

I was of course trying to do something bit more complex with Azure CLI, but this was the problem that wasted me quite some time.

And actually setting parenthesis like this seems to work as I expect:

("[1, 2, 3]" | ConvertFrom-Json) | ForEach-Object {Write-Host "Number: $_"}

And outputs:

Number: 1
Number: 2
Number: 3

Is this a piping issue in powershell or do I just not understand piping in powershell.

My powershell version is as follows:

> $PSversionTable

Name                           Value
----                           -----
PSVersion                      5.1.22000.282
PSEdition                      Desktop
PSCompatibleVersions           {1.0, 2.0, 3.0, 4.0...}
BuildVersion                   10.0.22000.282
CLRVersion                     4.0.30319.42000
WSManStackVersion              3.0
PSRemotingProtocolVersion      2.3
SerializationVersion           1.1.0.1