Can I use text messages, email, or AirDrop to send my pictures through Crowbox?

Sure, BUT Crowbox is different.

Crowbox lets you show nearby friends/family your pictures without giving them the pictures — or your phone.

Instead of passing your phone around or holding it at a distance you can show your photos on their devices. They may not want to own photos of your vacation or your children, but they’d probably love to see them.