Try placing all the pearlweed behind the wood instead, tidy up the substrate line along the glass a little(flatten it), tie the riccia down to some small pebbles and place those pebbles all along the front of the driftwood until it hits the back panel of glass. You'll have a more defined scape that way. As it is, the stems in front of the driftwood will end up blocking it and there won't be a "head" or "tail" to the scape and the riccia looks like it was randomly placed on the wood with no thought put into their placement.
I hope my comments don't offend you in any way. Just trying to help tidy up the aquascape a little.