The middle box is fine by the top and bottom aren't. Consider how a cube looks from underneath, the sides aren't spreading out, they're going away from you, up. Perspective is about points of convergence, as a shape stretches away from you, it's end point gets smallre, meaning that the edges along the cubes' sides will slowly come together as it lengthens away from you. Refer to guides on the topic.
AlexToolStudio
Hey people would told you to draws those
Cosmiccookie2000
What do you mean?