These 2 animals are used to describe older men and women on the 'dating scene'.

The silver fox implies an older wealthy man with grey hair (everyone calls George Clooney silver fox)

The cougar is an older woman who pursues younger men.

Why is only the age difference highlighted in the female? Also, the cougar is a beautiful and dangerous animal.

I think this is because men are threatened by her.

https://preview.redd.it/qvhjb7y46j951.jpg?width=1200&format=pjpg&auto=webp&s=7c9016735b49259c1c988b4fd6d456fbf4b65a00

https://preview.redd.it/7dv4tol16j951.jpg?width=640&format=pjpg&auto=webp&s=27a8574bf0f9d977830bbddf69c5d123cdb3103c