In this paper, we investigate the recent paper of Shakoor et al. [A. Shakoor,
I. Ali, S. Wali, A. Rehman, Some formulas on the Drazin inverse for the sum
of two matrices and block matrices, Bull. Iran. Math. Soc. 48 (2022)
351-366]. Here we prove that the main, additive result from the mentioned
paper is actually a corollary of one known result. Furthermore, we give new
representations for the Drazin inverse of anti-triangular block matrix,
which generalize some representations from current literature on the topic.