Réponse :
First reason is that you lie on your actual look.
Second reason is that you try to be "prettier" than you are already but you are gorgeous.
Third reason is that you can look older than you really are.
And fouth reason is that filters usuallly tries to make you face "perfect" and make your lips bigger, your nose smaller, make-up... but they are not real standard to have to be pretty.
Explications :
J'espère que cela t'aura aidé, bonne journée!