It is an Adobe Stock promo offer for which you are getting an Advertisement from your search history. It is not a compulsion to sign in for the promo.
Yes, and PLEASE BEWARE: it's a 'free 30-day trial', after which, you will be *automatically* signed up for a 1 year annual plan, billed monthly for $29.99/month, and if you cancel after this subscription starts, you'll be charged $29.99 for an early cancellation fee. I was bilked out of nearly $65 because of this practice. It's the same deceptive routine the 1-800 numbers that offer a 'free 30-day trial' of a product do to you. They count on you forgetting that if you don't manually cancel before the 30-day period ends, you are agreeing to an annual plan and they will get at least 2 months-worth of payments out of you because of the 'early subscription cancellation fee'.
Not impressed with this and Adobe shouldn't treat its customers this poorly. 30-day free trials are fine, but the automatic enrollment in an annual plan is NOT. I didn't even receive an email reminding me that the annual plan was about to go into effect. How hard would an email warning be? I certainly get plenty of other emails from you guys when you have something to sell me, but surprise, surprise - when it might save me money ... no email.