As the title says it is a compete the sequence.
There's a triangle, a circle and a 'U' shape. They each appear both 'normal', once with both halves mirrored along a vertical axis, and once with the left side intact and the right rotated 180 degrees.
left side of the U intact, right side rotated 180 degrees.
The reason it isn't a circle, triangle, and U is because of the second row. There is no way to move the triangle and U to get the circle while preserving their shape, therefore, they need to move the same way the circle will which gives you the shapes in the first row. the rows do not have the same moves to get to the end result although they do build on each other in number of moves. The first row has 0 moves, the second has 1, and the third has 2.
the third one in the first row.
Aaaand finally the .. squarish things?
Divide image in half, flip half; and reconstruct the whole image.