Meristems not all the same?

[plantbuddy]

I was looking at some orchid sources and came upon this statement, which puzzled me.

It indicates that not all mericlones are true-to-form, and that there is recognizable variation.

If this is the case,how does one tell if a mericlone is a true representation of the original?

quote-

"Blc. Goldenzelle
(C. Horace 'Maxima' AM/AOS x Blc. Fortune 'Golden Throne' HCC/AOS). One of the finest hybrids of the past ten years. Sturdy, extremely vigorous, fast growing plants with tight growth systems that often produce multiple leads. Full, beautiful flowers. Plants selected for this offering are some of the finest from the grex and are mature flowered varieties.
‘Lemon Chiffon' AM/AOS. Form ORC-LAB. $350.00. Form YWR. $100.00
Note: These are mericlones obtained from Stewart Orchids and are vigorous, heavy bulbed and leaved unlike many of the mericlones on the market. Full butter-yellow with red-purple dart in center of broad lip. Plants normally develop multiple leads. The ORC-LAB form is quite flat and yellow flowers are up to 6”. The center lines of the petals are slightly lighter yellow. The YWR form are slightly smaller, more yellow and more ruffled. All sizable plants with substantial bulbs. "