This is because facebook caches the page, so if that is the picture displayed first when facebook randomly caches the page, it will be the first one they display. The best way to avoid this is to upload and sort your photos as soon as possible after creating a property site. You can manually force facebook to update the cache by going here and entering the url: https://developers.facebook.com/tools/debug
That forces facebook to update the cache, so it will show the correct info.
It may still take several hours for facebook to update the cache, so please wait then try submitting the link again on facebook and it should work.