Is it kufr to buy and wear a Poppy or buy and use other things that have a picture of a Poppy?
The remembrance poppy is an artificial flower that has been used since 1921 to commemorate military personnel who have died in war, and represents a common or field poppy, Papaver rhoeas.
A poppy is sold and bought to commemorate the soldiers of World Wars. Small artificial poppies are often worn on clothing leading up to Remembrance Day/Memorial Day/Armistice Day.
The money given is spent on injured soldiers and the dead British soldiers families and other events etc. The money is also used for things like the Royal British Legion and to fund Recovery Centres around the country to help those badly injured to regain their health and other similar stuff, etc.