"These" brands may refer to any of your competitors, any of the vendors you buy from, or any of the brands that you look up to. A group of brands with something in common.
It refers to the other brands that have also chosen to invest in a particular driver, series, venue or team with you. If your brand is sponsoring a property, who else is there with you? What brands do you share space with? This zoomed-out look at your marketplace can provide striking insights.
The other brands involved are there for a reason. That reason can and very well may be the same reason you are there. Your audience choosing you over your competition will come down to how you communicate your "why," and the value you bring to them through your activation programs. Aligning your brand to the right property is important, but it's what you do with that property that will bring you lasting value.
Being seen next to your competition is especially beneficial when you are confident in what you have to offer.