[see more from Megan Fox at her primary site, Glass Bottom Games]
There's this standard advice that, on its face, looks kind of ridiculous. It goes something like:
"When a company is hiring for a QA person, for instance, they want a QA person - not a generalist. They want to know that you'll be happy in the QA position, and not actually gunning for production / programming / whatever position and viewing QA as a stepping stone."
Now you might look at that and think any number of things. But a generalist is more valuable! But few really want to work in QA, it's just a stepping stone position for most, and most know that! Just because someone wants to move up doesn't mean that they won't be happy just being in the industry and being able to work up in the mean time!
These are all true.
Yet none of them matter a whit.
A company doesn't put up a listing that says "Quality assurance technician" secretly hoping that a graphics programmer will apply. They put up that position because they have a vacancy in their QA department which they need filled ASAP. They want that vacancy filled by someone that will perform the role of quality assurance technician to the best of their abilities, that knows the job, that's really willing to dig into it and be the best dratted QA person that they can be. They do not want someone who is going to sit there looking busy, whilst quietly applying for every other internal job posting and getting disgruntled when they don't get the jobs.
Now I realize it doesn't have to be that black and white. You can really throw yourself into the QA role while still working at home on your portfolio, while still keeping your eyes open for another position. You can get yourself noticed as an amazing can-do person that stays late to get the job done, and slowly catch the eye of the production/code/art team, and gun for a role in the next project as your current project is winding down. This is all very true.
But when hiring? The company is still just looking for a QA person that will be happy as a QA person. So play the game.
Everyone knows that you're probably hoping for something else, and that's fine. Everyone also really does secretly like a generalist, so you should absolutely be one. But! You don't hammer on this as your primary selling point in your interview.
When you're interviewing for a QA position, show yourself off as the best dratted QA person you can possibly be. Talk up your experience with processes, with the deconstruction of problems. Explain how excellent you are at communicating with other people, and so on. Then, casually slip in that you're also an excellent Programmer, or Artist, and believe you can apply that especially well at running down difficult-to-grasp technical problems, or how you're very good at figuring out how to reproduce asset bugs, or whatever.
Be creative, but always apply it back to the position you're applying for. Casually mention how your other skills make you a better QA person, rather than thumping your generalist talents as making you useful in positions that you're not even being interviewed for / that are already staffed.
... and then, once you're hired? A few months in? Now you spring out as a generalist, now you talk to your artist friend and say that you'd be happy to help on this or that task after hours.
Now you make yourself useful as a generalist, but only after establishing how excellent a specialist you were for the position actually being offered.
This of course doesn't just apply to QA positions.
Artists? You need to figure out if you're more of a prop artist, a character artist, a texture artist, etc. What jobs are you applying for? That specialty should be what dominates your portfolio. Don't apply for an animator position and then have the front page of your portfolio full of concept art. Now once you're hired on as an animator, and it turns out you can volunteer to help with that piece of concept art when no one else has the time? That you can do up textures too, whatever? Hey, great! ... but that's after you're hired.
Programmers? What folks usually want to see is at least one polished game regardless of your specialty, maybe two, but past that, you should focus your portfolio down toward something. Physics, rendering, tools development, AI, whatever, but pick one and demonstrate that you can really nail it. Or if you're applying to multiple positions? Customize your portfolio for each, showing off your examples that are best suited to that position. Don't just huck up a portfolio with the 20 applications you've made in the last 3 years and make the hiring manager try and guess which ones demonstrate your specialty.
Specialization, and demonstration toward that specialization, is increasingly critical as you look at joining larger teams. Figure out what you're best at, and sell yourself as that to the best of your ability. Also mention the generalist talents, and maybe even mention them more in the interview if your sounding-out seems to indicate that they're responding to it... but only after you've first demonstrated what an amazing, perfectly-suited specialist you are for the position actually being offered.