Stunted autoflower

Could be a runt, could be stress... With an autoflower you get ~2 weeks of vege phase on average, then it's into flower and you have 3-4 more weeks of vege growth (stem elongation and leaf growth) before it ceases. Everything is the same as a photoperiod except the cause of how it switches gears. So, any less than optimal conditions diring that abrupt time will impact yield. The LST could have done it. It might be a runt. looks like you stripped it of leaves at some point becuase it's only small an immature leaves on the plant... i'd wager in this case it was more about how it was handled than anything out of your control - not trying to be mean about it. Fairly certain but can't be 100% certain. was fertilization methods part of it? maybe a small degree.. but i don't see major symptoms so it couldn't have been a major problem and there's always room for improvement of such things. hard to determine when only sugar leaves are present.