You cannot have private enough security measures for some NDA projects / Use Vimeo Instead / Better security. Trusted in Industry. / Feel free and encouraged to send TWO TAKES of each scene to display an ALTERNATE CHOICE.
Reps have a trained eye to see what needs strengthening and have a better idea of what Casting is looking for. If they are able to review your self tape then they are getting a glimpse into what the actor's audition is like and this can be very helpful.