With the originals, volunteers'eyes tended to stay longer on certain places in the image, but with the altered versions, they would flit across a piece more rapidly. As a result, the volunteers considered the altered versions less pleasurable when they later rated the work. In a similar study, Oshin Vartanian of Toronto University asked volunteers to compare original paintings with ones which he had altered by moving objects around within the frame.
"...when they later rated the work" means "...when they gave their opinion of the work afterwards"
"Moving objects around" means "Editing the picture (almost certainly using a software package like Photoshop) by cutting images of things or people from their original position and pasting them elsewhere". In this context the researcher would also have to fill in the spaces left by the cut and pasted elements with part of the background copied from other parts of the picture.
"In the frame" means "inside the original borders of picture"
So the whole clause "moving objects around in the frame" means changing the composition of the picture by changing the position of elements of the picture without changing the size or shape of the picture.
If you think of a well-known picture like the Mona Lisa the sort of thing that could have been done would be: move the figure from the centre to the right hand side; move the lake from the far left towards the centre; move the cascade from the right hand side to join up with the lake; and move the road from the left to the far right. This would change the composition from Leonardo's original so much that its pleasing symmetry would be destroyed.
The research finds that the volunteers would view the altered image differently from the original and would, later, say that the altered image was less attractive.