When dealing with nested maps that create an array you need to access, where you define the variable that holds the array is important. See the differences here.

nested_map_variable.rb

#Example 1
$myvariable= imgarray.map do |layouts|
  layouts[ 'layouts' ].map do |layout_name|
    layout_name[ 'layout_name' ]
  end
end
#Placing the variable at the beginning of the loop returns an array within an array:
#[["annie", "billy", "charlie", "danny", "eddy", "fergie", "granny", "henry", "jenny", "kelsey"]]

#Example 2
imgarray.map do |layouts|
  $myvariable= layouts[ 'layouts' ].map do |layout_name|
    layout_name[ 'layout_name' ]
  end
end
#Placing the variable one level down returns just one array:
#["annie", "billy", "charlie", "danny", "eddy", "fergie", "granny", "henry", "jenny", "kelsey"]