I just had the West Elm pillow that inspired this one in my hand the other day and found it very cute and springylicious and marvelously DIYable for the patient of soul.
Jessica at Sew Homegrown did the DIY, and I think her pillow looks even better than the inspiration.
See her tutorial at Sew Homegrown. Or save yourself the madness of cutting 60 to 80 circles and get the West Elm version on sale for $25 (cover only).
p.s. West Elm also has lots of slipcovered sofas on sale right now.