You are downloading the Camera 1020 XAP file v22.214.171.124 for Windows Phone. Camera 1020 is a free Productivity App: This app requires Windows Phone 8.1 (preview or final release).This is a camera app designed specifically for Lumia 1020 (or models with high resolution. You can now download the offline XAP package file to install & try it.
Download Locations for Camera 1020 126.96.36.199 XAP file
To try to install it manually from an SD card, you should choose one of the server location above to get the offline Camera 1020 XAP file, move the file to your phone's SD card and then tap 'Install local apps' in the phone's App list.