It's so hard to know what to do with toddlers. If it's something I knew DD would really enjoy and she was just having a bad moment, I'd probably try to divert her immediate attention to get through the tantrum so we could get to the good bit. I try to remember she's not acting that way to get at me personally and I shouldn't take it personally (I am the first to admit sometimes I fail in assuming that attitude, though). But I think of it as being kind of like when I get super grumpy and fussy and DH says "I think we need to get you a snack" and then once I've had that I shape right up.