How to mass-upload profile pictures to Exchange 2013

It's friday afternoon, an hour before the end of your shift. Biggest boss walkes into your office and says:
- It's good to see you being so happy to see me. I've got a job for you. You gotta load our new employees' high-resolution photos into our company's Exchange2013 immediately. You should be able to find all the 180 picture files on the fileserver. Actualy, it should have done yesterday. So... (dramatic pause)... have you done it yet ?

1. - Don't panic.
2. - Resize or cut those freaking profile photos to 648x648 pixels with a free smart photo viewer, for example with a batch job in Irfanview.
3. - Rename the files to match your users' login names, e.g. Bill Gates -- billgates.jpg - That's the trickiest part if your files are called user3412_10102014.png or whatever. That'd suck. Force your colleagues to name the files properly next time.
4. - Use this script. It reads all the files in the sourcedir, takes the username from filename and puts the picture into that user's corresponding Exchange attribute.

$sourcedir = "c:\temp\photos\"
$files = Get-ChildItem $sourcedir -Filter "*.jpg"
$files | ForEach-Object {

   $fullpath= $sourcedir + $_.Name
   $name = $_.BaseName
   write $fullpath
   write $name

   $photo = ([Byte[]] $(Get-Content -Path $fullpath -Encoding Byte -ReadCount 0))
   Set-UserPhoto -Identity $name -PictureData $photo -Confirm:$False
   Set-UserPhoto -Identity $name -Save -Confirm:$False
  
}

once ready... paste the following into your PS:
Set-OwaVirtualDirectory -ChangePasswordEnabled $true -SetPhotoEnabled $false -DisplayPhotosEnabled $true

Set-CASMailbox user -OWAMailboxPolicy Default 
or
Get-CASMailbox -ResultSize Unlimited | Set-CASMailbox -OWAMailboxPolicy Default

Curious why 648x648 is that dimension exactly? Nobody knows. Frankly. The point is you will end up with 3 different sized picture stored for each account in your AD and Exchange 2013 and Lync 2013 or Sharepoint 2013 (if you have any)

1. 48 x 48 pixels in AD thumbnailPhoto attribute field (If you upload a photo to Exchange 2013, Exchange will automatically create a 48 pixel by 48 pixel version of that photo and update the user's thumbnailPhoto attribute. Note, however, that the reverse is not true: if you manually update the thumbnailPhoto attribute in Active Directory the photo in the user's Exchange 2013 mailbox will not automatically be updated).
2. 96 x 96 pixels for use in Microsoft Outlook 2013 Web App and Microsoft Outlook 2013
3. 648 x 648 pixels for use in Lync 2013 and Sharepoint 2013