This link to Bonnie Hunter's Spiderweb pattern (one of many free patterns @ Quiltville.com) will show you how the blocks are constructed, and you can see how those tips are not cut off.
http://quiltville.blogspot.com/2005/...pider-web.html
Bonnie's patterns are really well done, with many pictures showing each step. You'll notice that the center (kite-shaped template) has the tip blunt. Then, working from each side, you'll be adding to it - and in adding that first strip of the spiderweb, or the piece of white in Jenny's quilt, first on one side then the other, that blunt bottom becomes a point. The blunt part is encased in the resulting seam.
It really is a pretty easy pattern; thank you for pointing it out. I like it much better with the solid background than the spiderweb that I did.