Yes, size matters when it comes to picots. These are small, medium and large picots all done with the same stitch count, creating three different looks. This is the Star in 2 Colors with Pearls by Inga Madsen from the book "Christmas Decorations in Tatting". Below you can see what they look like on the other side. I also did one without beads.
These are all done using vintage thread size 70. The white was a Lily the red a Coats and Clark thread with price tags 15 and 10 cents respectively.