I looked at your picture and it's showing your extruder....
A few things that can cause various amounts of shifting(lost steps)
-stepper drives are not adjusted properly. (need to increase current going to the motors)
-Firmware or print speeds are too high for your machine.(try lower print speeds)
-Belts are too tight
-Damaged belts(metal reinforcement/bands in the belts are broken)
-Motors are underdriven