A bit off topic, but I think the whole "shiny toy" perspective misses a lot. Both junior and senior developers are fundamentally thinking about maximizing the value they get from their employment. The value generally isn't "fun" and "shiny". I suspect that maps somewhat accurately to what a junior developer wants, but mostly because they don't have enough context (yet) to distinguish between "shiny" and "great for my career".
Anyway, the pitch for all of the above is "This job will be great for your career". Describe to junior developers what their next resume will look like. Lists of shiny tech probably work, but honestly think about what a great 3-5 year resume looks like and help them blow that out of the water. Describe to a senior developer how they'll have more agency and autonomy, how they'll be helping steer the organization at a strategic level, etc. A senior developer wants to be working on promising tech, but they need to be able to call shots at the same time. Otherwise, they're just a more experienced associate developer.
Or maybe the job won't be amazing for their career. I guess that's fine, but in that case you should be describing other benefits that make up for that.
All of that goes for all candidates: Male, female, married, single, junior, and senior. "Here's why this will be the best job you can take right now."
Other than the hostile and draining work environment, Pao's biggest complaint was that her employer wasn't giving her the career opportunities she thought she deserved. It wasn't tech but the major differences is what a shot looks like in an investment role versus a development role.