You are right, the application doesn't display contact photos, but this is already a known problem that the applications suffers from. This issue has been addressed by users on the application's page from Google Play where the product is hosted. You could leave a review with your problem or address it to the original developer. There are more chances the application will be fixed if the developer receives many notifications regarding this problem.
You can send an e-mail with your issues to the following e-mail address: support@invi.com