The episode "Grill, Interrupted" was aired on 2015's April's Fools' Day, the network ABC pulled a prank by featuring some hidden jokes in each of Wednesday's night's episodes. On Modern Family, instead of showing the Season 6 opening sequence, the version of the families holding the picture frames are from Season 1, so Lily is a baby, the Dunphy kids look super young and there's no trace of Baby Joe. Also, the painting in the foyer of Jay and Gloria's house. Normally, the painting by the front door depicts someone wearing flip-flops, but the shoes change to one of three different styles in various scenes.
Oddly used the wrong credits. Strange to see the season 1 looks again!