Why would you expect one firm to make super normal profit while another makes losses while they operate under conditions of perfect competition?

In a perfectly competitive market, firms are price takers which mean that they have no bearing on the market price. The one making supernormal profit could be due to

• efficiency and old in business hence could be operating at optimal point where it incurs low cost of production
• expansion of its business on large scale hence enjoying economies of scale

The  making losses could be due to

• inefficiency and being young in business and incurs high costs of production.
• Over expansion hence leading to diseconomies of scale