It’s the picture we should get at this stage:

Find in Internet a picture of flower, like this one shown on the picture:

Cut it out, using the Eraser Tool (E) and insert it on our picture.

Select now Filter>Filter Gallery>Artistic>Cutout

Press on the next combination of buttons now: Ctrl+Shift+U (Desaturate).

Make a copy of our flower and place the copy above the original one. Next enter the option Filter> Filter Gallery>Stylize.

Press now on this combination of buttons: Ctrl+Shift+I.

Apply for this layer the next adjustments:

We’ll get the next result: