This is Emeco’s $370 Navy chair (more info here):
This is Target’s ‘Cafe Aluminum Side Chair’, 2 for $249 (more info here):
Emeco’s registration number for the configuration of its chair is 2511360 (view in TARR here).
NY Times article ‘Look-Alikes Draw Lawyers Stares’ (reg req) reports on Emeco’s protest to Target. The source of Target’s chair, Euro Style, indicates that it will change the design of the chair.
UPDATE: Here is the Sandra Dining Set, 6 for $750 (hat tip Teresa):