This donation link currently takes you to a page that appears to be for donations for Mastodon. While I understand that you may be also running servers for Mastodon, Lemmy is a separate entity, and, as such, I believe its donations should be kept separate. When a user donates, I would wager that they don't want to feel like their donation may be used for a separate service that they may or may not use; they would want it to be used for exactly what they donated for.

It is possible that this may not be the case; the donation page name may just be a legacy thing, and not some combined pool of funds. If so, I strongly recommend adding some description to the page stating that that is the case, or better yet, simply rename it to lemmy.world donations.