First, you don't flush with epsom salts, you flush with plain pH adjusted water.
Second, 2tbsp/gallon is WAY too much magnesium.
Third, that pic on the right looks like an outdoor plant. Unless it is growing in a pot, you can't flush it. And if you just watered it with that much epsom salts... ooooh that's not good. But for now it looks healthy, why did you want to flush it to begin with?
The one on the left is stunted and definitely could use another gallon of plain water through it to wash out the epsom salts. Then wait until you see some new growth and you can start feeding 1/4 strength grow nutes, or a transplanting solution with vitamin B12 to promote root growth.