Trying to validate an object two different ways

Campaign.php

<?php

namespace AppBundle\Entity;

use Doctrine\ORM\Mapping as ORM;
use Symfony\Component\Validator\Constraints as Assert;

/**
 * Class Campaign
 * @package AppBundle\Entity
 * @ORM\Entity
 * @ORM\Table
 */
class Campaign
{
  // ....
  
  /**
	 * Image representing the sponsor of the campaign
	 * @var Image
	 * @ORM\ManyToOne(targetEntity="Image", cascade={"all"})
	 * @Assert\Valid
	 */
	protected $logoImage;
	
	/**
	 * Image representing the campaign
	 * @var Image
	 * @ORM\ManyToOne(targetEntity="Image", cascade={"all"})
	 * @Assert\NotBlank
	 * @Assert\Valid
	 */
	protected $heroImage;
	
	// ...
}

CampaignType.php

<?php


namespace AppBundle\Form\Type;

use Symfony\Component\Form\AbstractType;
use Symfony\Component\Form\FormBuilderInterface;
use Symfony\Component\OptionsResolver\OptionsResolverInterface;

class CampaignType extends AbstractType
{
	public function buildForm(FormBuilderInterface $builder, array $options)
	{
		$builder->add('logoImage', new ImageType, array('validation_groups' => array('campaign_logo_image')));
		$builder->add('heroImage', new ImageType, array('validation_groups' => array('campaign_hero_image')));
	}

	public function getName()
	{
		return 'campaign';
	}

	public function setDefaultOptions(OptionsResolverInterface $resolver)
	{
		$resolver->setDefaults(array(
			'data_class' => 'AppBundle\Entity\Campaign',
			'validation_groups' => array('campaign'),
		));
	}
}

Image.php

<?php

namespace AppBundle\Entity;

use Doctrine\ORM\Mapping as ORM;
use Symfony\Component\Validator\Constraints as Assert;
use Symfony\Component\HttpFoundation\File\UploadedFile;

/**
 * Class Image
 * Doctrine-managed image representation, based upon http://symfony.com/doc/current/cookbook/doctrine/file_uploads.html
 * @package AppBundle\Entity
 * @ORM\Entity
 * @ORM\Table
 * @ORM\HasLifecycleCallbacks
 */
class Image
{
  // ...

	/**
	 * @var UploadedFile
	 * @Assert\Image(minWidth="300", groups={"campaign_logo_image"})
	 * @Assert\Image(minWidth="900", groups={"campaign_hero_image"})
	 */
	protected $file;

	/**
	 * Sets file.
	 *
	 * @param UploadedFile $file
	 */
	public function setFile(UploadedFile $file = null)
	{
		$this->file = $file;
		if (isset($this->path)) { // We're updating - so save a reference to the old file, so we can clear it later
			$this->temp = $this->path;
			$this->path = null;
		}
	}

	/**
	 * @return \Symfony\Component\HttpFoundation\File\UploadedFile
	 */
	public function getFile()
	{
		return $this->file;
	}
	
	// ...
}

ImageType.php

<?php

namespace AppBundle\Form\Type;

use Symfony\Component\Form\AbstractType;
use Symfony\Component\Form\FormBuilderInterface;
use Symfony\Component\OptionsResolver\OptionsResolverInterface;

class ImageType extends AbstractType {
	public function buildForm(FormBuilderInterface $builder, array $options)
	{
		$builder->add('file', 'file', array('label' => $options['label'] ?: null));
	}

	/**
	 * Returns the name of this type.
	 *
	 * @return string The name of this type
	 */
	public function getName()
	{
		return 'image';
	}

	public function setDefaultOptions(OptionsResolverInterface $resolver)
	{
		$resolver->setDefaults(array(
			'data_class' => 'AppBundle\Entity\Image',
		));
	}
}