There are at least three other ways to approach this:

      user.try.profile.try.website.try.thumbnail

      user.trying{ |u| u.profile.website.thumbnail }

      user.trying.profile.website.thumbnail.resolve

It occurs to me the first could be fairly concise if we think of #s
as possessive:

      user.s.profile.s.website.s.thumbnail

Albeit it looks a bit odd.