Looks like it has pre flowers forming. If the plant is 4/5 weeks old I’m under the assumption this is normal for auto flowers, I have only done two grows myself so by no means a pro but of the 7 autos I have done they have all started to pre flower after around 4/5 weeks and they stretch for around 2/3 weeks after forming the pre flowers. The last two autos I did though I just fed them the veg nutes for longer and didn’t introduce the flower nutes until week 6 and it kept them in veg for longer and they started pre flowering at week 7 and were finished at week 14