A mobile user without the iPhone app who receives a shared video or photo on their phone will typically see an SMS message appear. 

The SMS message will include text indicating that you (as shown by your username) have shared a video or photo to them.

The SMS message is from the Thwapr "shortcode" which is 757575.

The title text of your video or photo will be shown along with a link to the video or photo. When the recipient clicks on the link, it will launch their mobile web browser and show a landing page with a thumbnail of the video or photo.  

When the user clicks the thumbnail on their phone , the video will play or the photo will be viewed.

The user receiving your video or photo can register for Thwapr if they want to comment on your media or upload and share their  own media.

They can also opt-out of receiving any SMS messages by texting "stop" to 757575.