Kann sie wirklich schon reif sein und woran kann es liegen?

That has to be one of the best trichome picture talking services I've ever seen! Sometimes certain phenotype will finish earlier or later. There really is no other reason

Meosis. Unlike how other cells divide (mitosis), sex gametes have their genes jumbled up during cell division. It is not an exact copy like when a normal cell divides. This is why even if you 'self' a plant you can get different traits expressed in the next generation... it is not a clone even if it has sex with itself, bwahah, There is much less diversity, and that is a problem, but still not a clone of the parent (singular). gametes are haploid cells - pollen or ovary in this case. visual aid from Britannica https://cdn.britannica.com/88/78588-050-8F99E222/formation-gametes-meiosis-process.jpg one cell becomes 4 haploid cells by the end. It divides twice but the 2nd division does not replicate the chormosomes. Mitosis -- https://cdn.britannica.com/87/78587-050-A85FBB5D/cell-rise-daughter-cells-mitosis-process.jpg You can see the gentic recombination does not occur in mitosis - that's where it gets jumbled up in meosis and diverse pollen cells or diverse ovaries that are not identical to each other.

Breeders give times based on averages...........a rough guess/approximation, more or less. Plants are organic beings, not robots.

Looks like one of them is simply a faster-maturing pheno, totally normal Even from the same strain and breeder, plants can vary by 1–3 weeks depending on phenotype, environment, and even pot size or root development. If trichomes on that one are already cloudy/amber while the other still has clear ones, just harvest them separately at peak ripeness. Better results that way