Visible crew/equipment: When they're all practicing the Charleston, while Bobby's watching from the stairs, everyone is shown dancing from different angles, and in the low angle shots facing the kitchen the top of the kitchen set is visible, particularly when Carol twirls her necklace.
Visible crew/equipment: As Mike gets up from the table after lecturing the girls, the boom mike's shadow becomes visible on his back. (00:15:00)
Answer: Much trivia has been written about "The Brady Bunch, " including the various interrelationships and dynamics among the members of the cast. For example, much has been written about why Robert Reed's Mike Brady did not appear in a couple of episodes, including the series finale, due to rancorous creative and artistic differences with series creator, Sherwood Schwartz. However, in contrast, I have never run across any reasons given why a particular child did not appear in specific episodes - only that the episodes were missed. This suggests the causes were likely unexceptional, such as illness, injuries, vacations, or real-life family obligations.
Michael Albert
Although those options ARE possible reasons, it just seems a bit ironic that this happened all in Season 2 ONLY and within a short amount of nearly consecutive episodes. Never happened during the other 5 years of the show at all.