Showing only first image %2F changes to %252F

Hi All.

I want to show just the first image / thumbnail from a multi upload.

So I have View As Custom with this:

$filesArray = my_json_decode($value);
$imageFile  = $filesArray[0];
$value = '<img alt="' . htmlspecialchars($imageFile["usrName"]). '" src= ".' .htmlspecialchars($imageFile["name"]). '">';

Some images work, but for some images the link fails. Eg:

IF the exact correct filename shown in the file browser is:
http_%2F%2Fstatic.theiconic.com.au%2Fp%2Frains-7378-386864-1_4n4mbmrv.jpg

Then I browse with Firefox to open the file, Firefox adds some characters:
http_%252F%252Fstatic.theiconic.com.au%252Fp%252Frains-7378-386864-1_4n4mbmrv.jpg

Why does firefox add these? How do I compensate in my code??

Thanks for any help,

Jim.