Дмитрий

{$_modx->runSnippet('pdoResources', [
	...params...
	'loadModels' => 'ms2gallery',
	'leftJoin' => [
		'Image' => [
			'class' => 'msResourceFile',
			'on' => 'modResource.id = Image.resource_id AND Image.parent = 0 AND Image.rank = 0',
		],
		'Thumb' => [
			'class' => 'msResourceFile',
			'on' => 'Image.id = Thumb.parent AND Thumb.path LIKE "%afisha%"', // здесь afisha это название thumbnails из источника файлов, заменить на своё.
		]
	],
	'select' => [
		'modResource' => '*',
		'Image' => 'Image.url as image',
		'Thumb' => 'Thumb.url as thumb',
	]
])}