Is (-3,4) the reflection of (3,4) over the y axis?
If we look the location of the point on the graph, it is located at x=3, y=4. To find the reflection, we need to cross the y axis which would be x=-3. The y coordinate will be the same since we are crossing the x axis and the point will still be above the x-axis.
If we reflect across the x-axis, then the x-coordinate will stay the same but the y-coordinate will change sign but have the same value.