Change the image preview height to 200px.
// Set preview height to 200px with flexible aspect ratio.
gform.addFilter('image_hopper_filepond_config', function(config, FilePond, $form, currentPage, formId, fieldId, entryId, files, inputField) {
config.styleItemPanelAspectRatio = null
config.filePosterHeight = 200
return config
}, 20 )