plastic flags? (Southport PR9)

Haven't a clue what these are, they look like 3 plastic flags and remnants of some construction.
*A very kind and helpful Freegler has just let me know what the 'construction' bits are: ........'the construction is a bin bag holder there should be a top bit that traps the top of the bag so it holds the bag open'* Grateful thanks for that helpful bit of information though not sure it would be any use to someone.