There are always two vegetarian dishes and four vegetarian dishes. If Xiaoming buys 1 vegetarian dishes, there are two possibilities. He bought two vegetarian dishes.
It can be considered that if you buy a vegetarian dish first, there are four possibilities, and then buy one of the remaining three, there are three possibilities, so there are 3×4= 12 possibilities in total, but after ignoring the order, there are only half, that is, six possibilities, because the redundancy contained in 12 may be upside down.
Similarly, if you buy two meat dishes, you can only buy two of them, so there are only 1 possibilities, and the total * * * is 1×6 = 6 possibilities.