How is 7 a peak?

it is not, it is the index of a peak. in this kata, you have to return an array of peaks and an array of their indices

I don't know what values take WA for x-axis there, but they are wrong. Try with this other one: https://www.wolframalpha.com/input?i=plot+%5B%280%2C3%29%2C+%281%2C+2%29%2C+%282%2C+3%29%2C+%283%2C+6%29%2C+%284%2C+4%29%2C+%285%2C+1%29%2C+%286%2C+2%29%2C+%287%2C+3%29%2C+%288%2C+2%29%2C+%289%2C+1%29%2C+%2810%2C+2%29%2C+%2811%2C+3%29%5D&lang=es

I guess OP confusion came from the wrong graphic representation.

You're looking for all the peaks (think: mountain peaks), not just the highest one. The image you showed displays them both pretty well.

I'm a little bit confused:

[Example: pickPeaks([3, 2, 3, 6, 4, 1, 2, 3, 2, 1, 2, 3]) should return {pos: [3, 7], peaks: [6, 3]} (or equivalent in other languages)]

How is 7 a peak?

https://www.wolframalpha.com/input?i=plot+%5B3%2C+2%2C+3%2C+6%2C+4%2C+1%2C+2%2C+3%2C+2%2C+1%2C+2%2C+3%5D

That plateau after the peak is not a plateau-peak, it's just a plateau.

At index 20 there is a plateau-peak.

for arr [1,2,5,4,3,2,3,6,4,1,2,3,3,4,5,3,2,1,2,3,5,5,4,3],
expected { pos: [ 2, 7, 14 ], peaks: [ 5, 6, 5 ] } to deeply equal { pos: [ 2, 7, 14, 20 ], peaks: [ 5, 6, 5, 5 ] }. How ?

expected { pos: [ 2, 3 ], peaks: [ 3, 2 ] } to deeply equal { pos: [ 2 ], peaks: [ 3 ] }
assert.deepEqual(pickPeaks([2,1,3,2,2,2,2,5,6]), {pos:[2], peaks:[3]});

why?

{'pos': [3, 7], 'peak': [6, 3]} should equal 
{'pos': [3, 7], 'peaks': [6, 3]}
                     ^

They're not.

{'pos': [3, 7], 'peak': [6, 3]} should equal {'pos': [3, 7], 'peaks': [6, 3]}
{'pos': [3, 7], 'peak': [6, 3]} should equal {'pos': [3, 7], 'peaks': [6, 3]}
{'pos': [3, 7, 10], 'peak': [6, 3, 2]} should equal {'pos': [3, 7, 10], 'peaks': [6, 3, 2]}
TF is this? These are completely SAME (pls help)

Finding thepeaks is not difficult, but your wanted solution with a Map and List is confusing, why not use a Map and put a position and a peakheight together?

https://www.codewars.com/kata/5279f6fe5ab7f447890006a7/discuss#64f5b8c72b610bbbb906767f

What is "peaks"??????????????????????

why for [3,2,3,6,4,1,2,3,2,1,2,2,2,1] the result is [3, 7, 10] why doenst [3, 7, 10, 12]

After a few hours, I still don't understand what I did, but it works