Events Calendar PRO: Photo View: Reverse the display order of events per page (i.e. the same events are displayed, just with the nearest-upcoming on the bottom instead of on the top).

functions.php

<?php
/**
 * Events Calendar PRO: Photo View: Reverse the display order of events per
 * page (i.e. the same events are displayed, just with the nearest-upcoming
 * on the bottom instead of on the top).
 *
 * @link https://gist.github.com/cliffordp/c180a419c53b0243ac4811f7a6e0f02c
 * @link https://theeventscalendar.com/support/forums/topic/post-page-order/
 */
function photo_view_reorder_posts( $posts ) {
	remove_filter( 'the_posts', 'photo_view_reorder_posts' );
	return array_reverse( $posts );
}

function photo_view_reorder_listen( $query ) {
	if (
		'photo' === $query->get( 'eventDisplay' )
		|| tribe_is_ajax_view_request( 'photo' )
	) {
		add_filter( 'the_posts', 'photo_view_reorder_posts' );
	}
}

add_action( 'tribe_events_pre_get_posts', 'photo_view_reorder_listen' );