To send video or photo messages to the Educator simply do the following:
Step 1 - Log into your account. If you don't know how to log into your account see this article
Step 2 - Choose the option "Create message".
Step 3 - Select the child(ren) the message is about
Step 4 - Write the message
[OPTIONAL] Step 5 - Go to the Camera icon and choose a photo/video from your Image Gallery and voilà!
This way you will be able to send a message to which only the Educator and the Manager have access :)
If you want to send a message that only the Management has access to, see this article