We'll create fresh WordPress site with Simple Photoswipe installed. You have 20 minutes to test the plugin after that site we'll be deleted.
Simple Photoswipe extends WordPress’ built in gallery functionality and uses Dmitry Semenov’s awesome Photoswipe gallery library.
You can customize some of Photoswipes options at Settings > Simple Photoswipe.
Important Note: In order to use Photoswipe zoom effect correclty you need to disable thumbnail cropping!
By default your images will be cropped to proportional 150×150 thumbnails. I would reccomend to set a bigger thumbnail size (as shown in screenshot 4) and re-upload your images. In case you don’t want to re-upload your images I would recommend another plugin to automatically recrop your uploaded images.
Demo
You can see a live demo here