How to ask trickily to your friend to send her pic ?

Tricky can have different meanings.

More often than not trickery is dishonest, not a nice way to treat a friend, and definitely not good for a friendship - likely to cause a loss of trust.

If you must ask, do so openly, simply, directly, honestly.
But don't be surprised if she says no.
Sending photographs over the net is notoriously dangerous for women.

A woman who does it is either totally innocent, naïve or stupid.
Or she's a different type of woman, one who doesn't care about the possible consequences, neurotic and unconsciously self-destructive,

Maybe, just maybe, she reached a point of trusting you.
But given that few relationships last,
and rejected and angry men can take revenge,
even in trust, sending a photo is foolish.

Show me your titties usually works

If they’re your friend why can’t you ask them directly?

Ask if she has snap

Tita pic?

Ure disgusting

Is she supposed to remain a friend? 🤔

If you want to "trick" her then you are not her friend. Good for her for denying your nasty offers. To hell with you