What is this Image Verification?

It’s a CAPTCHA, which is an acronym for “Completely Automated Public Turing Test”.

A CAPTCHA is a security test to determine whether or not the user of this Contact Form is human (since people can read distorted text - i.e. text where the letters and numbers are not the same size and/or font - but most current computer programs cannot).

Therefore, CAPTCHA Image Verification security tests ensure that only human visitors will actually submit forms rather than spamming bots (malicious programs) that are browsing the web from site to site.