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Why can the two enantiomers of glyceraldehyde not be made identical without breaking bonds?

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Two diagrams show the three-dimensional structure of a methane molecule: panel A uses a ball-and-stick model with a central carbon atom connected to four hydrogen atoms in a tetrahedral arrangement, while panel B illustrates the bond angle of 109.5 degrees and bond length of 1.09 angstroms between carbon and hydrogen atoms. — isomerism Tetrahedral geometry of methane: (A) stick-and-ball model and (B) diagram showing bond angles and distances. (Plain bonds represent bonds in the plane of the image; wedge and dashed bonds represent those directed toward and away from the viewer, respectively.)

The two enantiomers of glyceraldehyde cannot be made identical because they are non-superimposable mirror images of each other, a property known as chirality or handedness.12

Much like a pair of human hands, the two isomers possess the same constituent parts but are oriented differently in space. Specifically, the hydrogen and hydroxyl groups attached to the central carbon atom at position 2 are arranged such that one structure cannot be rotated or reoriented to perfectly match the other. Because these spatial arrangements are fixed, the only way to convert one enantiomer into the other is to break and reform the chemical bonds connecting these groups to the central carbon.134