Beautiful.
Your first two sweaters actually use different colour knitting techniques. The Ralph Lauren uses intarsia knitting, whereas the red one uses jacquard knitting where the colours are stranded across the back (in the case of the 'snowflake' emblems it's actually a combination of jacquard and intarsia). Both techniques will result in some loose ends, which should be woven in for a professional finish. But weaving in is a time consuming process.