In the presented situation, are you approaching an uncontrolled intersection?

In the video you are driving along a street in a town; on the right, before the junction, there are signs D-1 "priority road" and under it B-21 "no left turn". You are not approaching an uncontrolled junction of equal roads - right of way here is set by signs. The answer is: no.

An uncontrolled junction of equal roads is one where right of way is not set by any signs and the right-hand rule from the Road Traffic Act applies; the Regulation on road signs and signals provides warning sign A-5 "crossroads" for it. Here there is sign D-1, which marks the beginning or continuation of a priority road - so the intersecting roads are minor roads and their drivers give way to you. The additional sign B-21 prohibits turning left at the nearest junction, and with it making a U-turn, so you may go straight on or turn right. The conclusion for the exam: when you see D-1, A-7, B-20 or plate T-6 before a junction, the junction is not a junction of equal roads. When you have right of way, you still exercise particular caution and watch the side road entrances, but you do not have to give way to anyone.

Legal basis: § 43 para. 1, § 22 para. 1 and 2 and § 5 para. 1 of the Regulation on road signs and signals; Art. 25 para. 1 of the Road Traffic Act (Prawo o ruchu drogowym)