I agree with Sophie.
But there are points about the weight that can lead people to think it is by Paul Ysart:
a) Paul Ysart is more widely known, than Salvador Ysart, to have made weights with sulphides
b) The garland of canes is very well formed
c) The base is flat polished
However, I have yet to see an "obvious" Paul Ysart weight with the Robert Burns sulphide, whereas I have seen several Salvador Ysart examples (which may have been made in the 1930s or at the Ysart Brothers (Vasart) works).
Points against this weight being by Paul Ysart are:
a) As Sophie pointed out, the sulphide is not "good enough" for work by Paul
b) The Burns sulphide is known in several weights attributed to Salvador Ysart
c) The cane used for the garland is well known in weights by Salvador / Ysart Brothers (Vasart)
d) In one of the eBay images, the ground is seen to be quite distorted
The flat polished base is a tricky feature for analysis. I do not know whether a flat-bed grinder was ever used at the Ysart Brothers (Vasart) works. But there are several known weights attributed to Salvador Ysart (as opposed to daily Ysart Brothers output) that have a flat polished base. Perhaps the indication here is that such weights were made by Salvador in the 1930s (or a bit earlier?)
An interesting feature is that the garland of canes is set well above the dark ground. That is a not a feature I have seen (at least, not that I recall) in Paul Ysart weights. But I do have a PY sulphide weight in which it could be said that the the canes "float" over the ground. However, the "ground" is not in the form usually known - it is actually a "cup" of dark powdered (but thick-looking) glass rising from the base and up the sides for a short distance. The canes are set a very short distance from the top edge of the dark "cup". Generally, where Paul used a coloured ground in a millefiori weight he set the canes directly on the ground.
Another point of interest is that some people may claim that the complex cane used for the garland of the eBay weight is good enough to have been made by Paul Ysart. Well, yes, that is true! A study of over 400 Ysart canes from weights and other items, all attributed to Salvador Ysart / Ysart Brothers (Vasart), shows that there are lots of very good complex canes which can be said to equal the quality of most canes by Paul Ysart. Checking against Paul Ysart work, it is known that some canes do appear in items by "both sides of the family". However, of the 400+ canes studied, only 14 were found to be matched in work by Paul - and the cane in the eBay weight is not, so far, one of them.
I'll be quiet now.