I bought some 300 bulb Icicle lights sets at Target.

On the box it says (word for word):

"Electrical rating: 120V, 0.6 Amps, 72 watts

Connect up to 210 Watts or 2 sets (600 lights) of the same TARGET 300
icicle light set."

Lousy grammar aside, if the sets are rated at 72 watts and you can
"connect up to 210 watts", why the "2 sets (600 lights)" limitation?

What will happen if I connect 3 or 4 sets together - other than the
Christmas Lights police coming after me?

Thanks!