Comparison between LiI absorption lines observed on March 12 and 14, corresponding to photometric maximum and minimum. In the top plot there is no difference in line depth, showing that no veiling is detectable with brightness increase. In the bottom plot we added veiling to the spectrum at photometric maximum to demonstrate how a spot with temperature of 10 000 K and f = 5% would affect the line depth if it were the main cause of the observed photometric variations.