Reverses the order of posts on each individual photo view page (but does not reverse the sequence as a whole ... for TEC/ECP 4.5/4.6). In other words, this doesn't necessarily mean we'll see the furthest-in-the-future event first, rather it means each page on photo view will contain the same range of events but in the reverse order.

reorder-photo-view_reverse-by-page.php

<?php
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' );