Top down sweaters have their advantages. One advantage is that there are usually fewer seams, if any. Another is that they work really well with A-line sweaters. They also can show off certain stitch patterns better when starting at the top of the garment.
Then there are the sleeves; like a more fitted sleeve? Hate setting in sleeves? Top-down sleeves are usually easier. Add cut outs in the sleeve cap and a saddle shoulder and it’s a cinch.
In this sweater, the saddles are worked first and continue down to the underarm in a strip. Stitches are picked up at the underarm, some stitches are cast on, and the strap stitches are worked in the round to form the sleeve below the underarm. Super easy, and lots of fun.
The lace pattern involves twisted stitches and add flare and therefore the A-line shaping is without increases.