Hello Antonio,
I am really sorry for the delay of this reply as it is a weekend for us here. Unfortunately right now this is not configurable but you can edit the theme file /components/com_easysocial/themes/wireframe/groups/category.item.php and remove the block of codes below,
            <div class="es-widget">
                <div class="es-widget-head">
                    <div class="pull-left widget-title"><?php echo JText::_( 'COM_EASYSOCIAL_GROUPS_RANDOM_ALBUMS' );?></div>
                </div>
                <div class="es-widget-body">
                    <?php if ($randomAlbums) { ?>
                        <ul class="widget-list-grid">
                        <?php foreach( $randomAlbums as $album ){ ?>
                            <li>
                                <div class="es-avatar-wrap">
                                    <a href="<?php echo $album->getPermalink();?>" class="es-avatar es-avatar-sm"
                                        data-original-title="<?php echo $this->html( 'string.escape' , $album->get( 'title' ) );?>"
                                        data-es-provide="tooltip"
                                        data-placement="bottom"
                                    >
                                        <img alt="<?php echo $this->html( 'string.escape' , $album->get( 'title' ) );?>" src="<?php echo $album->getCover( 'square' );?>" />
                                    </a>
                                </div>
                            </li>
                        <?php } ?>
                        </ul>
                    <?php } else { ?>
                    <div class="fd-small">
                        <?php echo JText::_('COM_EASYSOCIAL_GROUPS_NO_ALBUMS_HERE'); ?>
                    </div>
                    <?php } ?>
                </div>
            </div>