When static cubemaps are used, it is assumed that the objects at skybox texture are far away, so it is not problem that the view does not change when camera moves.
However, when using dynamic cubemap we include the objects near the camera. Thus, for example; we have giant glass in front of camera, and we have objects in front of glass and we need to calculate refraction. Because, we give only a vec3 to texture function in glsl, the coordinate on the glass is ignored. For example; the refraction vector at the middle of glass is vec3(0, -0.2, -0.6) and the refraction at the right bottom corner of glass is also vec3(0, -0.2, -0.6). Thus, the colors of both coordinates will be same, but it should not. How we can handle this problem?
To solve this issue you can use parallax corrected cubemaps, this allows you to create "local cubemaps" (with a reference bounding box) instead of "infinite cubemaps".
Seb Lagarde has a very nice article explaining it all in details (see the "Parallax correction for local cubemaps" chapter).