In a small living room, floor space is the actual constraint, and a pouf and a bean bag chair solve it differently. Here's the real difference, not just the style one.
Footprint and flexibility
A pouf like the Belgique Pouf has a smaller, more defined footprint than a full bean bag chair, and its flatter profile makes it easy to tuck under a console table or slide out of the way when you need the floor space back. A bean bag chair, by comparison, needs to stay wherever it's sized to sit.
How each one gets used
A bean bag chair is a primary seat. A pouf is more flexible: footrest, extra seat, or a small side surface, which matters more in a small room where one piece often has to do more than one job.
Fabric and safety
Belgique's 100% polyester velvet cover sits on the same Canadian-made virgin polystyrene fill as the rest of the Gouchee lineup, flammability tested per CPSC 16 CFR Part 1640 and meeting ASTM safety standards.
Which one to pick
If you need a primary seat, get the bean bag chair. If you need a flexible, smaller-footprint piece that can move around the room as needed, the pouf is the better fit for a small space.