I can't tell what that bottom coordinate is labeled as but I am going to call it Z.
I = (-3 , -2)
E = (-3 , -3)
Q = (2 , -4)
Z = (0 , -5
To reflect acrossed y = -2 means that
I = (-3 , -2)
E = (-3 , -1)
Q = (2 , 0)
Z = (0 , 1)
All you are doing is taking the y coordinate on each of them and basically mirroring it.
Kind of like how you look into a mirror you see a reflection all your doing is changing the y values to be the opposite of what they are when you mirror them across y = -2.
I coordinate stays at (-3 , -2) because the y coordinate (x , y) is at y = -2. Y is vertical on the graph and x is horizontal.
