The second half will go in a different dimension because there might not be too many chances for Brighton to be with the ball. However, Brighton might give us a surprise package in the second half.
I hope that surprise doesn't happen. Arsenal should be able to maintain the advantage that has been obtained. It's just that we don't see many opportunities that can be obtained by Arsenal players. Although not too often making attacks, we can see Brighton also has several opportunities from shots although not accurate. If Arsenal gives Brighton a game to develop and freely make attacks, maybe the surprise you are talking about can really happen.