i came across a photo where the gradient looks like it s smeared from cream. It is hard to explained by saying so here is the Let say i create 2 similar shapes with the gradient pattern then adjust the opacity but the edges will still remain. But in the example the edges are appeared to be soft and hard randomly. Thanks in advance !
You could use a transparency gradient to blend the shapes.
(A) I duplicated a vector shape with some gradients and changed a bit the values of them.
(B) And added gradient transparency.
(C) The result
(D) But you can even add some gaussian blur to the shapes and again play with the transparency. This layer or object is above the previous one.
(E) The result
To this point, all "effects" are reversible (depending on the software you use)
One more thing is to actually do is take some blur or smear tool on your software and smear a bit.