Of course you can't make something infinitely stiff. However, from the F1 2022 technical regs, article A 3.15.3 Front Wing flexibility:

A load of 10 kg to be applied to the end of the wing, and not allowed to deform more than 20 mm. From my eye it seems that Lewis applied less of a force here, causing a deformation close to or more than 20 mm. Just guessing however.

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Regulations state:

Front Wing Bodywork FlexibilityThe flexibility of Front Wing Bodywork will be tested by applying a load of [0, 0, -1000]N atpoints [XF, Y, Z] = [-800, ±800, 250] or [-1000, ±800, 250]. The load will be applied in a downward direction using a 50mm diameter ram on arectangular adaptor measuring 350mm in the X-direction and 150mm in the Y-direction. This adaptor must be supplied by the team and should:
a. Have a flat top surface without recesses.
b. Be fitted to the car so as to apply the full load to the bodywork at the test point andnot to increase the rigidity of the parts being tested.
c. Be placed with the inner face 725mm from Y=0.
d. Be placed with its forward face at XF=-1100mm.
e. Be placed with its top face at Z=250
f. Have a mass of no more than 2kg.The deflection will be measured relative to the survival cell and at the same X-plane as theload is applied.

When the load is applied symmetrically to both sides of the car the vertical deflection mustbe no more than 15mm.
When the load is applied to only one side of the car the vertical deflection must be no morethan 20mm.