Sitecore PowerShell Extensions example transferring items between servers using rainbow serialization and spe remoting. You will want to be using SPE 5.1 or newer when transferring media items.

CopyContentWithRainbow.ps1

Import-Module -Name "SPE"

$session = New-ScriptSession -user "admin" -pass "b" -conn "https://spe-a"
$yaml = Invoke-RemoteScript -ScriptBlock {
    $homeId = "{110D559F-DEA5-42EA-9C1C-8A5DF7E70EF9}"
    Get-ChildItem -Path "master:" -ID $homeId -WithParent -Recurse | 
        ConvertTo-RainbowYaml
} -Session $session

$session2 = New-ScriptSession -user "admin" -pass "b" -conn "https://spe-b"
Invoke-RemoteScript -ScriptBlock {
    $using:yaml | Import-RainbowItem
} -Session $session2