TVs of this spec and age have depths of between 17mm and 100mm. The 55PUS6561 has one of the thicker depths (85 millimeters) amongst similar spec televisions of this age.
It may also be worth also looking at one of the alternative 85mm thick televisions currently available including because of their better review scores, the 55PUS6501 (£619.97), or the 55PUS6401 (£579) both from Philips.
Televisions with a thicker depth that might be worth looking at include the Philips 55PUS6551 (£749) (85mm).
What does "depth" mean?