The photos put into Xiaomi's mobile phone gallery have become smaller because you have turned on the smart photo slimming function. The solution is to open the photo album and press the menu button for a long time, and then turn off the smart photo slimming.

Details are as follows:

1. Open the photo album in the phone settings;

2. Open the photo album and press and hold the menu button;

3. Just turn off the smart photos.