How do I make my validation error message more specific

I have a form where one of the inputs is named “photo”. I’m also using HTML5’s “multiple” option on the input to allow several photos to be uploaded at once. This means the resulting $request->input('photo') is an array of UploadedFIles and the builtin validator for file size was failing.

So I’ve written my own rule by extending the validator in my AppServiceProvider like so:

Validator::extend('photosize', function ($attribute, $value, $parameters, $validator) {
    foreach ($value as $file) {
        if ($file->getSize() > 5000000) {
            return false;
        }
    }

    return true;
});

Then in the controller I can use the rule and add an error message like so:

$validator = Validator::make(
    $request->all(),
    ['photo' => 'photosize'],
    ['photosize' => 'Uploaded file exceeds size limit 5MB']
);

However this means regardless which file was too big the error message is the same. Is it possible to have that information in the error message?