gistfile1.cs

public void Execute(UploadPhotoCommandHandler, ...)
{
  ...
  var profile = ...;
  .. //some validations if profile exists and so on
  profile.UploadPhoto(@command.photo);
  _profileRepository.Save(profile);
}

...
...
...
public class Profile
{
  public Guid Id { get; private set; }
  
  public Photo Photo { get; private set; }
  ...
  ...
  ...
  
  public void UploadPhoto(Photo photo)
  {
    if (photo.Size > sth && photo.MimeType != "image/jpeg")
    {
      throw new ArgumentException("some msg");
    }
    
    Photo = photo;
  }
}