Blocks with "do" are different to Blocks with "{}"

blocks

#!/usr/bin/env ruby                                                                                                                                                                                         

puts "Count with {}"                                                                                                                                                                                        
puts [[1,1],[2],[3],[4,3]].count { |elements| !elements.all? { |element| element == elements.first } or elements.size == 1 }                                                                                
puts "----------------------"

# Response: 
# Count with {}
# 3
# ----------------------

puts "Count with do"                                                                                                                                                                                        
puts [[1,1],[2],[3],[4,3]].count do |elements|                                                                                                                                                              
  !elements.all? { |element| element == elements.first } or elements.size == 1                                                                                                                              
end                                                                                                                                                                                                         
puts "----------------------" 

# Response:
# Count with do
# 4
# ----------------------

puts "Map with {}"                                                                                                                                                                                          
puts [[1,1],[2],[3],[4,3]].map { |elements| !elements.all? { |element| element == elements.first } or elements.size == 1 }                                                                                  
puts "----------------------"

# Response:
# Map with {}
# false
# true
# true
# true
# ----------------------

puts "Map with do"                                                                                                                                                                                          
puts [[1,1],[2],[3],[4,3]].map do |elements|                                                                                                                                                                
  !elements.all? { |element| element == elements.first } or elements.size == 1                                                                                                                              
end                                                                                                                                                                                                         
puts "----------------------"

# Response:
# Map with do
#  #<Enumerator:0x00000001dd68b8>
# ----------------------