The birds don't seem to flare off it. They just didn't want to land anywhere. When birds committed, they did it without hesitation. I must say though, that that blind is new, installed like the weekend before the season started so it doesn't have as much grass as we would like and there is quite a bit of evidence of the excavation and such around it that just couldn't be covered up. Next season, when the grass grows in around it, it will be sweet!
The birds seemed to be more interested in a grassy shoreline about 200yds away where the winter wheat was close to the waters surface.