On WPResidence the images you or one of your users upload are saved like using WordPress default mechanism.
More exactly : all images are saved as post attachments and can be managed via Media section of the wordpress admin interface.
More information about attachment : http://www.wpbeginner.com/glossary/attachment/
If you did not change the path of the upload images then the theme will upload the images in the wordpress default folder. The folder is wp-content/uploads/ . Also WordPress will organize your uploads into month- and year-based folders