Double images in Sitemap

Hi, i am using this plugin..its very nice..I used SEO by Yoast plugin to handle seo issues..but i have noticed that there are two images attached to every post … one from

https://www.example.com/wp-content/uploads/2/2014/08/image.png
and
one from
https://www.example.com/wp-content/thumbs/fgd/M/image.png, in every post.

suppose that my total games are 200 hundreds in number but images are 400 hundered..

One image is linked two times from diffrent URLs .please give me solution.

https://www.ads-software.com/plugins/myarcadeblog/