Scammers increasingly looking to transfer potential victims from email over to SMS, as mobile devices make it easier to facilitate attacks. Scammers generally ask a victim to take a picture of the back of a message from a victim who is being targeted by a scammer who asks for their cell phone number. Scammer knows that the fraud is working the second they receive a reply containing the requested phone number. The actor is immediately placed in a strong position, and the actor places greater expectations to make a more instantaneous reply than that of its email counterpart.”]
Source: https://www.agari.com/email-security-blog/bec-goes-mobile/