It's hard to say looking at those pictures. how were they oriented on the bed?
I suspect that you may have loose drive belts on the bed, the gantry, or both. Or something else not tight like a screw or the wheels are not firm against the beams. When printing anything where the the motors need to come to a quick stop, like reversing direction or making right angles, if they accelerate down too quick and some thing is loose, it will cause a vibration or over extension.
Check your printer make sure everything is tight. with the printer off, loosen the pulley mount on the bed and pull it tight as you move the bed back and forth, re tighten the screws. this will remove any slack in the X direction. Then do the same for the gantry belt. ( there are tighteners available to print from this sight, but you need a good print first.
Reset your slicer settings. and re-level (calibrate) your bed.
If you are printing PLA, set the slicer for .1 or .2 mm height. use a .4mm nozzle, Printing with Brim. Bed temp at 60. nozzle temp at 210. slow the print speed down to 40 mm/sec. Initial layer to 20 or 30 mm/sec, no support. re-slice the cube, and print it. For some PLA's 210 maybe too hot, but it is a good start and makes good prints that have no layer problems. if you find it sagging, reduce temp to 205.
before removing it from the bed take another picture, or two from different angles.
If it prints well, you are good to go, if not post the pictures.