I see two goals in that paragraph:

Fundraiser for Kamala

Encourage Kamala to make a mastodon account and promote on it over other social media

People have already donated hundreds of millions of dollars to her via more official channels. This is a grassroots fundraiser targeted specifically at mastodon users (and now the fediverse at large because of this post) with the stated incentive of trying to encourage Kamala to use mastodon over other platforms. You could chalk the mastodon but up as secondary but there isn't even a third thing in that paragraph for the mastodon portion to be less important than. Given the amount of press the Harris campaign has already received, it seems like this fundraiser's primary purpose is to promote mastodon via contributing to the campaign and tacitly asking Kamala to sign up.

If mastodon users wanted to donate to the campaign, they have probably been exposed to several other avenues to do that before they would have even seen this. So what's the point of doing a special "fediverse only" fundraiser? Apparently it's to encourage her to create an account. It's pandering and I don't see a point in shilling a super special fediverse fundraiser for a candidate who's already drowning in small donation money when that money could be used to promote the fediverse in a much more meaningful way