All three devices have four cameras as well, each equipped with a main, wide-angle, macro, and a time-of-flight (ToF) camera. While both the 20 Pro and the 20L use a 48MP main sensor, 20 Pro uses a 6P lens, a wider aperture, and features optical image stabilization.
The 20L+ uses a higher resolution 64MP camera. It’s not clear why TCL didn’t install the higher resolution sensor on the higher-end device.
The TCL 20L. Source: TCL
The 20 Pro also boasts a higher resolution 16MP ultra-wide and 5MP macro camera whereas the other two devices use an 8MP and 2MP camera respectively.