Adenium arabicum question

[majcka]

Hello all.

I have a question or maybe thoughts here. I got seeds of Adenium arabicum last year (from Aiko). I saw them in january 2014:

Aiko - jan 2014.JPG (43.36 KiB) Viewed 864 times

And again in april 2014 (seeds from the same parcel):

Aiko - apr 2014.JPG (41.71 KiB) Viewed 864 times

Then again I asked him to send more seeds and saw them in february 2015:

Aiko - feb 2015.JPG (41.69 KiB) Viewed 864 times

Here are on one pic:

Aiko - Adenium arabicum.JPG (80.85 KiB) Viewed 864 times

They grow in the same medium on the same conditions....but the difference is obvious. The biggest one is in bigger pot becouse it outgrowed the old one.

What on earth is happening? True is I sawed them in different time, but not that much. Or did I?