Can someone explain me logic behind this code? what if I change spaces between first *print(end=" change")*

size = 7
m = (2 * size) - 2
for i in range(0, size):
    for j in range(0, m):
        print(end=" ")
    m = m - 1 
    for j in range(0, i + 1):
        print("* ", end=' ')
    print(" ")