If a campaign has a logo you want to re-use you have two options to re-use the logo.
1. Copy the Campaign
2. Download the logo straight from the campaign
1. To copy the campaign - Select 'Other' in the campaign manager and then select 'Copy'. You'll be asked to give it a new name.
2. In the campaign manager open the campaign and select 'Design'. Once the design manager is open, Right Mouse Click the logo and select 'Save As...'. Download the logo and reuse in another campaign.