That's right. The compound on the left and it's mirror image are one and the same, so the molecule is achiral. For them to be enatiomers the original compound and its mirror image have to be non-superimposable - that is, you can't get from one to the other just by rotating them around in space.
Try this. Get some plasticine and matches. Colour your matches with felt pens. Make a model where you have four different matches stuck in the plasticine pointing to the vertices of a tetrahedron. Also make the mirror image. No matter how you rotate the models around you can't get them to line up exactly. But if two of the matches are the same colour you can.
The first example is two enantiomers. The second example is when the compound is achiral, like your question, because it has a plane of symmetry.