While the tulip device is the typical cut-out seen on SOMECs' lugwork, some builders preferred to use shorter-sleeved lugs for one reason or another. These lugs didn't have enough surface area to carve a tulip into them, so a heart-shape or wing-shape was used. Some didn't use cut-outs at all, preferring instead to thin down the lugs to nothing.

It doesn't point towards greater or lesser quality, just a different builder's style. (As SOMEC doesn't mean a bike is built according to a single person's design, since they were all custom anyway, but built to a high standard of quality in materials, construction, and finish.)