Gifted brand shoot- is it worth it?

I got a DM on Instagram about a shoot for a beauty brand (1.1M followers) that is unpaid, but they will gift products and of course photos. I have only been modeling since January and haven't booked a paid job yet, but am trying to do test shoots to build my portfolio. The shoot images/ videos will be used on their website and social media. My agent said I am allowed to do it, but that he doesn't recommend it because with them using my images on their website, it could cause conflict with future beauty brands (that actuallybwant to pay me)! It's hard for me to turn down the opportunity because I haven't gotten a paid gig yet, but if I do this shoot and then it does cause conflict with a paid shoot later, I will be kicking myself! Would love some advice- I know people say not to work for free, but is it better to not work at all?!