Ah okay, that explains it. If that is the case, you need to edit the template override in /templates/office/html/com_easysocial/helpers/html/login.php and remove the codes below from line 148 - 191
<div class="o-grid__cell">
<div class="es-login-box__msg">
<?php if ($this->config->get('registrations.mini.enabled') && !$this->isMobile() && $showRegistrations) { ?>
<div class="si-login-box-msg">
<form method="post" action="<?php echo JRoute::_('index.php');?>" data-registermini-form>
<div class="register-wrap">
<div class="si-login-box-msg__hd-title"><?php echo JText::_('COM_EASYSOCIAL_LOGIN_NO_ACCOUNT');?></div>
<div class="si-login-box-msg__hd-desc"><?php echo JText::_('COM_EASYSOCIAL_LOGIN_REGISTER_NOW');?></div>
<?php foreach ($fields as $field) { ?>
<div class="es-register-mini-field" data-registermini-fields-item><?php echo $field->output;?></div>
<?php } ?>
<div class="t-text--center">
<button class="btn btn-es-primary btn-block" type="button" data-registermini-submit>
<?php echo JText::_('COM_EASYSOCIAL_LOGIN_REGISTER_NOW_BUTTON');?>
</button>
</div>
</div>
<?php echo $this->html('form.action', 'registration', 'miniRegister'); ?>
</form>
</div>
<?php } else { ?>
<div class="si-login-box-msg">
<div class="si-login-box-msg__hd">
<div class="si-login-box-msg__hd-title"><?php echo ucfirst($this->jConfig->getValue('sitename')); ?></div>
<div class="si-login-box-msg__hd-desc"><?php echo JText::_($loginPretext); ?></div>
</div>
<?php if ($showRegistrations) { ?>
<div class="si-login-box-msg__bd">
<div class="si-login-box-msg__bd-title"><?php echo JText::_('COM_EASYSOCIAL_LOGIN_NO_ACCOUNT');?></div>
<div class="si-login-box-msg__bd-desc"><?php echo JText::_('COM_EASYSOCIAL_LOGIN_REGISTER_NOW');?></div>
<div>
<a href="<?php echo ESR::registration();?>" class="btn btn-es-default btn-block"><i class="fa fa-globe"></i> <?php echo JText::_('OFFICE_REGISTER_NEW_ACCOUNT'); ?></a>
</div>
</div>
<?php } ?>
</div>
<?php } ?>
</div>
</div>