Why do most dudes lift weights? Usually to get stronger and bigger. What is more important? I think they both are. What will be noticed first? Depends on who's noticing. Often when you look in the mirror you will see the same person you saw 6 months ago. You will be the last person to notice a physical change. If you've been a skinny dude for years that is who you will see in the mirror unless you change how you see yourself.
What you should look at first is your strength gains. Are you getting stronger? Are you lifting more weight now than you were 6 months ago? Do you feel stronger during your day?
If your answer is yes chances are your physique has changed as well. Did your arms go from 12" to 24"? No but I bet your shirts are tighter. Thats not because they shrunk. It's because of the work you're putting in is paying off. Maybe you're not where you want to be yet and that's fine. Who is? That's why we keep working and moving forward. That's why we break PRs. You don't ever want to settle but it's good to acknowledge the gains you've made and know it's just the beginning.
If your answer is no and you're still working hard, take a look at your nutrition. Are you eating enough of the right muscle building foods? Are you getting enough protein? Are you eating often enough? This is commonly the missing component in the muscle gaining plan.
Bottom line is if you're training hard to get bigger and stronger, and you noticed you are definetly stronger, stop looking so hard for the difference in the mirror. It's there. You're becoming a bad ass! You train like a bad ass warrior who takes no prisoners. Quit looking in the mirror like a diva. Keep working hard. Stay focused. Nutrition! Nutrition! Nutrition!
Train Like a Warrior
Get Strong. Stay Strong.