You take the top off, you push the metal neck of the brush downward all the way down to reveal the brush. This brush is to be used for mineral veil for touch ups to your makeup throughout the day for that fresh, lively look. This is completely optional, but this can be used for foundation as well if you choose. I WAS going to use this for foundation, but I have a retractable brush and Flawless Face Brushes that can do just as good of a job. A retractable brush is a bit cheaper than this brush which is catered for mineral veil. The retractable brush is mainly for foundation.
You can't store foundation in this. Have you tried Sephora's Sifter Jars? They're empty, but you can fill them with your favorite things like foundation, veil (the loose powder version) or blush. Eye shadow is optional, but there is so many eyeshadows out there you may not even need a sifter for that. It's only $3.00 and I recently ordered 6; 2 for foundation, 2 for concealer and 2 for blush.
There is a refillable buffing brush, but I would rather swirl tap and buff myself versus a brush that may give me too much on my face. I haven't tried the refillable brush yet. Good idea for some, but I'm not sure if it would work for me or not just yet.
There are refillable compacts on the BE website too. A bit more in cost, but if you fear of losing your main source, you can always store a little of it into a compact or the Sephora sifters. I would rather lose a $3 sifter than my whole 26 or 28 dollar foundation jar, you know?
I have makeup for my swim bag, my purse, for hotel visits and one I use for when I feel like putting on makeup at home just because. This line of makeup has bettered my skin so just wearing it for the fun of it has only helped my skin and self esteem.