Error during Drupal installation: MySQL support not included in PHP
Recommend setting MAMP to use PHP5.6 if you have that option.

The screenshots show MAMP is set to use PHP7, but CiviCRM isn't ready for PHP7 yet. 

(PHP7 removes ext/mysql in favour of ext/mysqli and ext/pdo_mysql. CiviCRM looks for ext/mysql, and the installer test is bailing out when it detects that this isn't supported.)

CiviCRM's PHP requirements are documented in the CiviCRM wiki.